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EXAMINING THE U.N. INTERGOVERNMENTAL 

PANEL ON CLIMATE CHANGE PROCESS 

HEARING 

BEFORE THE

COMMITTEE ON SCIENCE, SPACE, AND 

TECHNOLOGY 

HOUSE OF REPRESENTATIVES 

ONE HUNDRED THIRTEENTH CONGRESS 

SECOND SESSION 

MAY 29, 2014 

Serial No. 113–77 

Printed for the use of the Committee on Science, Space, and Technology 

( 

Available via the World Wide Web: http://science.house.gov 
(II) 

COMMITTEE ON SCIENCE, SPACE, AND TECHNOLOGY 

HON. LAMAR S. SMITH, Texas, Chair 

DANA ROHRABACHER, California 

RALPH M. HALL, Texas 

F. JAMES SENSENBRENNER, JR., 

Wisconsin 

FRANK D. LUCAS, Oklahoma 

RANDY NEUGEBAUER, Texas 

MICHAEL T. MCCAUL, Texas 

PAUL C. BROUN, Georgia 

STEVEN M. PALAZZO, Mississippi 

MO BROOKS, Alabama 

RANDY HULTGREN, Illinois 

LARRY BUCSHON, Indiana 

STEVE STOCKMAN, Texas 

BILL POSEY, Florida 

CYNTHIA LUMMIS, Wyoming 

DAVID SCHWEIKERT, Arizona 

THOMAS MASSIE, Kentucky 

KEVIN CRAMER, North Dakota 

JIM BRIDENSTINE, Oklahoma 

RANDY WEBER, Texas 

CHRIS COLLINS, New York 

BILL JOHNSON, Ohio 

EDDIE BERNICE JOHNSON, Texas 

ZOE LOFGREN, California 

DANIEL LIPINSKI, Illinois 

DONNA F. EDWARDS, Maryland 

FREDERICA S. WILSON, Florida 

SUZANNE BONAMICI, Oregon 

ERIC SWALWELL, California 

DAN MAFFEI, New York 

ALAN GRAYSON, Florida 

JOSEPH KENNEDY III, Massachusetts 

SCOTT PETERS, California 

DEREK KILMER, Washington 

AMI BERA, California 

ELIZABETH ESTY, Connecticut 

MARC VEASEY, Texas 

JULIA BROWNLEY, California 

ROBIN KELLY, Illinois 

KATHERINE CLARK, Massachusetts 
(III) 

C O N T E N T S 

May 29, 2014 

Page 

Witness List ............................................................................................................. 2 

Hearing Charter ...................................................................................................... 3 

Opening Statements 

Statement by Representative Lamar S. Smith, Chairman, Committee on 

Science, Space, and Technology, U.S. House of Representatives ..................... 8 

Written Statement ............................................................................................ 9 

Statement by Representative Eddie Bernice Johnson, Ranking Member, Committee on Science, Space, and Technology, U.S. House of Representatives .... 10 

Written Statement ............................................................................................ 12 

Witnesses: 

Dr. Richard S.J. Tol, Professor of Economics, University of Sussex 

Oral Statement ................................................................................................. 14 

Written Statement ............................................................................................ 16 

Dr. Michael Oppenheimer, Albert G. Milbank Professor of Geosciences and 

International Affairs, Department of Geosciences, Princeton University 

Oral Statement ................................................................................................. 24 

Written Statement ............................................................................................ 26 

Dr. Daniel Botkin, Professor Emeritus, Department of Ecology, Evolution, 

and Marine Biology, University of California, Santa Barbara 

Oral Statement ................................................................................................. 35 

Written Statement ............................................................................................ 38 

Dr. Roger Pielke Sr., Senior Research Scientist, Cooperative Institute for 

Research in Environmental Sciences, and Professor Emeritus of Atmospheric Science, Colorado State University 

Oral Statement ................................................................................................. 53 

Written Statement ............................................................................................ 55 

Discussion ................................................................................................................. 67 

Appendix I: Answers to Post-Hearing Questions 

Dr. Richard S.J. Tol, Professor of Economics, University of Sussex ................... 96 

Dr. Michael Oppenheimer, Albert G. Milbank Professor of Geosciences and 

International Affairs, Department of Geosciences, Princeton University ....... 102 

Dr. Daniel Botkin, Professor Emeritus, Department of Ecology, Evolution, 

and Marine Biology, University of California, Santa Barbara ......................... 105 

Dr. Roger Pielke Sr., Senior Research Scientist, Cooperative Institute for 

Research in Environmental Sciences, and Professor Emeritus of Atmospheric Science, Colorado State University ......................................................... 109 

Appendix II: Additional Material for the Record 

Article submitted for the record by Representative Lamar S. Smith, Chairman, Committee on Science, Space, and Technology, U.S. House of Representatives ........................................................................................................... 134 
Page

IV 

Article submitted for the record by Representative Marc Veasey, Member, 

Committee on Science, Space, and Technology, U.S. House of Representatives ....................................................................................................................... 137 
(1) 

EXAMINING THE U.N. INTERGOVERNMENTAL 

PANEL ON CLIMATE CHANGE PROCESS 

THURSDAY, MAY 29, 2014 

HOUSE OF REPRESENTATIVES, 

COMMITTEE ON SCIENCE, SPACE, AND TECHNOLOGY, 

Washington, D.C. 

The Committee met, pursuant to call, at 11:02 a.m., in Room 

2318 of the Rayburn House Office Building, Hon. Lamar Smith 

[Chairman of the Committee] presiding. 
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Chairman SMITH. The Committee on Science, Space, and Technology will come to order. 

Welcome to today’s hearing titled ‘‘Examining the U.N. Intergovernmental Panel on Climate Change Process.’’ I will recognize myself for an opening statement and then the ranking member for her 

opening statement. 

The United Nations Intergovernmental Panel on Climate Change 

recently released three working group reports on climate science focused on physical sciences, impacts and adaptation, and mitigation. 

These documents make up the 5th Assessment Report. Similarly, 

the White House recently rolled out its National Climate Assessment, which takes a closer look at climate change and policy in the 

United States. 

Both the IPCC and the White House’s documents appear, in my 

view, to be designed to spread fear and alarm and provide cover for 

previously determined government policies. The reports give the 

Obama Administration an excuse to try and control more of the 

lives of the American people. 

The IPCC’s goal is an international climate treaty that redistributes wealth among nations. The Administration’s goal is to impose 

greenhouse gas regulations, which will stifle economic growth and 

lead to hundreds of thousands of fewer jobs. 

On the heels of these catastrophic predictions, the President 

plans to announce next Monday his most costly climate regulations: 

new climate standards for power plants. The Administration’s regulatory agenda will hit workers and families hard but have no 

discernable impact on global temperature. One analysis used IPCC 

assumptions and found that if the United States stopped all carbon 

dioxide emissions immediately, the ultimate impact on global temperature would only be 0.08 degrees Celsius by 2050. 

Serious concerns have been raised about the IPCC, including 

lack of transparency in author and study selection, and inconsistent approaches to data quality, peer review, publication cut-off 

dates, and the cherry-picking of results. 

Significantly, the scientists working on the underlying science for 

the IPCC defer to international politicians when they develop a socalled Summary for Policy Makers. This really amounts, of course, 

to a summary by policy makers. 

The document is disseminated ahead of the actual scientific assessment and provides biased information to newspapers and headline writers around the world, who gobble it up. 

Dr. Robert Stavins of Harvard University, who served as a lead 

author for the IPCC, recently criticized this process as generating 

‘‘irreconcilable conflicts of interest’’ that compromise scientific integrity. He wrote that ‘‘any text that was considered inconsistent 

with their interests and positions in multilateral negotiations was 

treated as unacceptable.’’ The bias is there for all to see. 

Following the 2007 assessment, key IPCC claims about the melting of Himalayan glaciers, the decline of crop yields, and the effects 

of sea-level rise were found to be completely erroneous and derived 

from non-peer-reviewed sources. 

In 2010 the InterAcademy Council identified ‘‘significant shortcomings in each major step of IPCC’s assessment process.’’ 
9 

We all know that predictions are difficult and that the only certainty about projections far into the future is that they will be 

wrong. Incredibly, the IPCC predicts to the year 2100 and beyond. 

The White House’s Climate Assessment implies that extreme 

weather, hurricanes and severe storms are getting worse due to 

human-caused climate change. The President claims that droughts, 

wildfires and floods ‘‘are now more frequent and more intense.’’ But 

the underlying science from the IPCC itself shows these claims are 

untrue, yet the Administration keeps repeating them. 

The President and others often claim that 97 percent of scientists 

believe that global warming is primarily driven by human activity. 

However, the study they cite has been debunked. While the majority of scientists surveyed may think humans contribute something 

to climate change, and I would agree, only one percent said that 

humans cause most of the warming. So the President has misrepresented the study’s results. 

We should focus on good science, rather than politically correct 

science. The facts should determine which climate policy options 

the United States and world considers. 

The IPCC and White House reports acknowledge that the United 

States has achieved dramatic reductions in emissions. The White 

House’s National Climate Assessment recognized, for example, that 

‘‘U.S. CO2 emissions from energy use declined by around nine percent between 2008 and 2012.’’ 

U.S. contributions to global emissions are dwarfed by those of 

China, the world’s largest emitter of greenhouse gases. And China 

shows no signs of slowing down. 

The Obama Administration should stop trying to scare Americans and then impose costly, unnecessary regulations on them. The 

President says there is no debate. Actually the debate has only just 

begun. 

When assessing climate change, we need to make sure that findings are driven by science, not an alarmist, partisan agenda. 

[The prepared statement of Mr. Smith follows:] 

PREPARED STATEMENT OF CHAIRMAN LAMAR S. SMITH

The United Nations Intergovernmental Panel on Climate Change (IPCC) recently 

released three working group reports on climate science—focused on physical 

sciences, impacts and adaptation, and mitigation. These documents make up the 

Fifth Assessment Report. 

Similarly, the White House recently rolled out its National Climate Assessment, 

which takes a closer look at climate change and policy in the U.S. 

Both the IPCC and the White House’s documents appear to be designed to spread 

fear and alarm and provide cover for previously determined government policies. 

The reports give the Obama Administration an excuse to control more of the lives 

of the American people. 

The IPCC’s goal is an international climate treaty that redistributes wealth 

among nations. The Administration’s goal is to impose greenhouse gas regulations, 

which will stifle economic growth and lead to hundreds of thousands of fewer jobs 

each year. 

On the heels of these catastrophic predictions, the President plans to announce 

next Monday his most costly climate regulations—new climate standards for power 

plants. 

The Administration’s regulatory agenda will hit workers and families hard but 

have no discernable impact on global temperature. One analysis used IPCC assumptions and found that if the U.S. stopped all carbon dioxide emissions immediately, 

the ultimate impact on global temperature would only be 0.08 degrees Celsius by 

2050. 
10 

Serious concerns have been raised about the IPCC, including lack of transparency 

in author and study selection, and inconsistent approaches to data quality, peer review, publication cut-off dates, and the cherry-picking of results. 

Significantly, the scientists working on the underlying science for the IPCC defer 

to international politicians when they develop a so-called ‘‘Summary for Policy Makers.’’ This really amounts to a ‘‘Summary by Policy Makers.’’ 

The document is disseminated ahead of the actual scientific assessment and provides biased information to newspapers and headline writers around the world, who 

gobble it up. 

Dr. Robert Stavins of Harvard University, who served as a lead author for the 

IPCC, recently criticized this process as generating ‘‘irreconcilable conflicts of interest’’ that compromise scientific integrity. He wrote that ‘‘any text that was considered inconsistent with their interests and positions in multilateral negotiations was 

treated as unacceptable.’’ The bias is there for all to see. 

Following the 2007 assessment, key IPCC claims about the melting of Himalayan 

glaciers, the decline of crop yields, and the effects of sea level rise were found to 

be completely erroneous and derived from non-peer reviewed sources. 

In 2010 the InterAcademy Council identified ‘‘significant shortcomings in each 

major step of IPCC’s assessment process.’’ 

We all know that predictions are difficult and that the only certainty about projections far into the future is that they will be wrong. Incredibly, the IPCC predicts 

to the year 2100 and beyond. 

The White House’s Climate Assessment implies that extreme weather, hurricanes, 

and severe storms are getting worse due to human-caused climate change. The 

President claims that droughts, wildfires, and floods ‘‘are now more frequent and 

more intense.’’ But the underlying science from the IPCC itself shows these claims 

are untrue. Yet the Administration keeps repeating them. 

The President and others often claim that 97 percent of scientists believe that 

global warming is primarily driven by human activity. However, the study they cite 

has been debunked. 

While the majority of scientists surveyed may think humans contribute something 

to climate change, and I would agree, only one percent said that humans cause most 

of the warming. So the President has misrepresented the study’s results. 

We should focus on good science, rather than politically correct science. The facts 

should determine which climate policy options the U.S. and world considers. 

The IPCC and White House reports acknowledge that the U.S. has achieved dramatic reductions in emissions. The White House’s National Climate Assessment recognized, for example, that ‘‘U.S. CO2 emissions from energy use . . . declined by 

around 9% between 2008 and 2012 . . . ’’ 

U.S. contributions to global emissions are dwarfed by those of China, the world’s 

largest emitter of greenhouse gases. And China shows no signs of slowing down. 

The Obama administration should stop trying to scare Americans and then impose costly, unnecessary regulations on them. 

The President says there is no debate. Actually the debate has only just begun. 

When assessing climate change, we need to make sure that findings are driven 

by science, not an alarmist, partisan agenda. 

Chairman SMITH. That concludes my opening statement, and the 

gentlewoman from Texas, Ms. Johnson, the ranking member of this 

committee, is recognized for her opening statement. 

Ms. JOHNSON. Thank you very much, Mr. Chairman, and good 

morning to all. I want to join the Chairman in welcoming our witnesses to this morning’s hearing. 

Today our Committee will hear testimony about the process that 

is followed in carrying out the scientific assessments of the U.N.’s 

Intergovernmental Panel on Climate Change. I hope that today’s 

hearing will be followed by a hearing at which scientists from the 

IPCC can actually present the findings of the 5th Assessment, because those findings are quite sobering and important for us to 

hear. 

In the meantime, while the topic of today’s hearing is a legitimate one, namely, how the IPCC process can be improved, I am 

concerned that the real objective of this hearing is to try to under-
11 

cut the IPCC and to cast doubt on the validity of climate change 

research. 

For the benefit of members who were not here in 2011, I would 

note that we had a hearing on this same topic back then, and the 

testimony to be given today echoes some of the claims made then. 

Ultimately, however, those claims were shown to be unfounded, yet 

here we are again. 

The reality is that the IPCC assessment is unprecedented in its 

scope and inclusiveness. The United States, along with 194 other 

nations, has arrived at a rigorous and open process that yields the 

most comprehensive and objective assessments of the scientific literature relevant to the understanding climate change and its associated risks. We need only look at the results of the previous assessments to realize how much the IPCC has contributed to our understanding of climate change. 

The latest assessment will be completed in October with the release of a synthesis report that integrates the results of each working group. Again, the IPCC’s message is clear: the climate is changing, humans are playing a significant role, and the time for meaningful action is now. All over the country, Americans are observing 

and responding to a changing climate. In Texas, my home state, 

record droughts and other severe weather events are putting a significant strain on regional economies and presenting new challenges to the state’s infrastructure and its ability to respond to 

these escalating threats. Developing timely solutions to these challenges is critical, and the IPCC provides policy makers with the 

factual basis to do just that. 

We are likely to hear today that political agendas distort the 

IPCC’s Summary for Policy Makers to make the impacts sound 

worse than they are or that the climate models or data the scientific assessments are based on are flawed. But we know that is 

not the case. In fact, if anything, the IPCC process of developing 

a consensus arguably results in a summary with more conservative 

estimates than some scientists believe are warranted, estimates 

that understate the impacts of climate change. 

Let us be clear: the IPCC’s summary document is policy-neutral 

and faithful to the underlying science. It is not a new assessment 

of the same information. It is not intended to be a substitute for 

the full assessment. 

Mr. Chairman, we have a responsibility to listen to the facts and 

act to protect the American people from the growing risk of changing climate. The IPCC makes clear to anyone who will listen that 

the science is well established and well accepted by the vast majority of climate scientists. We cannot continue to turn a deaf ear to 

the pleas from our constituents to start working towards solutions. 

This hearing is really a missed opportunity to consider the findings of the latest IPCC report and the kinds of actions the United 

States should be considering, and I—and as I stated earlier, I hope 

that we will have such a hearing in the coming months. 

In closing, I am committed to working with my colleagues on 

both sides of the aisle to develop policies that address these new 

climate realities. But we are going—we are not going to get very 

far if we spend our time continually revisiting a scientific debate 

that has already been settled. Nor will we get far if we continue 
12 

a recent practice on this Committee of seeming to question the 

trustworthiness and integrity of this Nation’s scientific researchers. 

That does them a disservice and does not reflect well on this Committee. 

Mr. Chairman, climate change is real, its impacts are real, and 

the need to act is real. I sincerely hope that we will soon be able 

to work together to develop constructive policies to deal with 

changing climate. 

Thank you, and I yield back. 

[The prepared statement of Ms. Johnson follows:] 

PREPARED STATEMENT OF RANKING MEMBER EDDIE BERNICE JOHNSON

Good morning. I want to join the Chairman in welcoming our witnesses to this 

morning’s hearing. Today our Committee will hear testimony about the process that 

is followed in carrying out the scientific assessments of the U.N.’s Intergovernmental Panel on Climate Change. I hope that today’s hearing will be followed by 

a hearing at which scientists from the IPCC can actually present the findings of the 

5th Assessment, because those findings are quite sobering and important for us to 

hear. 

In the meantime, while the topic of today’s hearing is a legitimate one, namely, 

how the IPCC process can be improved, I am concerned that the real objective of 

this hearing is to try to undercut the IPCC and to cast doubt on the validity of climate change research. 

For the benefit of Members who were not here in 2011, I would note that we had 

a hearing on this same topic back then, and the testimony to be given today echoes 

some of the claims made then. Ultimately, however, those claims were shown to be 

unfounded. Yet here we are again. 

The reality is that the IPCC assessment is unprecedented in its scope and inclusiveness. The United States, along with 194 other nations, has arrived at a rigorous 

and open process that yields the most comprehensive and objective assessments of 

the scientific literature relevant to understanding climate change and its associated 

risks. We need only look at the results of the previous assessments to realize how 

much the IPCC has contributed to our understanding of climate change. 

The latest assessment will be completed in October with the release of a synthesis 

report that integrates the results of each working group. Again, the IPCC’s message 

is clear: the climate is changing, humans are playing a significant role, and the time 

for meaningful action is now. All over the country, Americans are observing and responding to a changing climate. In Texas, record droughts and other severe weather 

events are putting a significant strain on regional economies, and presenting new 

challenges to the state’s infrastructure and its ability to respond to these accelerating threats. 

Developing timely solutions to these challenges is critical, and the IPCC provides 

policymakers with the factual basis to do just that. We are likely to hear today that 

political agendas distort the IPCC’s summary for policymakers to make the impacts 

sound worse than they are or that the climate models or data the scientific assessments are based on are flawed. But we know that is not the case. In fact, if anything, the IPCC process of developing a consensus arguably results in a summary 

with more conservative estimates than some scientists believe are warranted-estimates that understate the impacts of climate change. 

Let us be clear: the IPCC’s summary document is policy-neutral and faithful to 

the underlying science. It is not a new assessment of the same information. It is 

not intended to be a substitute for the full assessment. 

Mr. Chairman, we have a responsibility to listen to the facts and act to protect 

the American people from the growing risks of a changing climate. The IPCC makes 

clear to anyone who will listen that the science is well established and well accepted 

by the vast majority of climate scientists. We cannot continue to turn a deaf ear 

to the pleas from our constituents to start working towards solutions. 

This hearing is a missed opportunity to consider the findings of the latest IPCC 

report and the kinds of actions the U.S. should be considering, and as I stated earlier, I hope that we will have such a hearing in the coming months. 

In closing, I am committed to working with colleagues on both sides of the aisle 

to develop policies that address these new climate realities. But we aren’t going to 

get very far if we spend our time continually revisiting a scientific debate that has 

already been settled. Nor will we get far if we continue a recent practice on this 
13 

Committee of seeming to question the trustworthiness and integrity of this nation’s 

scientific researchers. That does them a disservice and does not reflect well on this 

Committee. Mr. Chairman, climate change is real, its impacts are real, and the need 

to act is reaI. I sincerely hope that we will soon be able to work together to develop 

constructive policies to deal with that changing climate. 

Thank you, and I yield back. 

Chairman SMITH. Thank you, Ms. Johnson. 

I will now proceed to introduce our witnesses today. Our first 

witness is Dr. Richard S.J. Tol, Professor of Economics at the University of Sussex and a Professor of Economics of Climate Change 

at the Institute for Environmental Studies at VRIJE University in 

Amsterdam. I know you made a big effort to be here today, and 

that is appreciated. Previously, Dr. Tol was a Research Professor 

at the Economic and Social Research Institute in Dublin, the Michael Otto Professor of Sustainability and Global Change at Hamburg University, and an Adjunct Professor at Carnegie Mellon University. Dr. Tol is ranked among the top 25 most-cited climate 

scholars in the world. He has written over 200 journal articles and 

authored three books. He specializes in the economics of energy, 

environment and climate. Dr. Tol has been involved with the IPCC 

since 1994, serving in various roles in all three working groups. 

Most recently, he served as a coordinating lead author in the economics chapter of Working Group II for the 5th Assessment Report. 

Dr. Tol received his Ph.D. in economics from the VRIJE University 

in Amsterdam. 

Our second witness today is Dr. Michael Oppenheimer, the Albert G. Milbank Professor of Geosciences and International Affairs 

at Princeton University. Previously, Dr. Oppenheimer served as 

Chief scientist at the Environmental Defense Fund. Dr. 

Oppenheimer also was a coordinating lead author in the risk and 

vulnerabilities chapter of Working Group 2 for the 5th Assessment 

Report. Dr. Oppenheimer received his Ph.D. in chemical physics 

from the University of Chicago. 

Our third witness today is Dr. Daniel Botkin, Professor Emeritus 

at the Department of Ecology, Evolution and Marine Biology at the 

University of California at Santa Barbara. He also teaches biology 

at the University of Miami. Dr. Botkin also served as a Professor 

at Yale University’s School of Forestry and Environmental Studies 

and at George Mason University. In 1970, Dr. Botkin developed the 

first successful computer model of the effects of climate change on 

forests and species. Recently, Dr. Botkin served as an expert reviewer for the United Nations’ IPCC’s 5th Assessment Report and 

reviewed the recently released National Climate Assessment. Dr. 

Botkin received his Ph.D. in biology from Rutgers University. 

Our final witness is Dr. Roger Pielke, Senior Research Scientist 

at the Cooperative Institute for Research and Environmental 

Sciences, a joint institute of the National Oceanic and Atmospheric 

Administration and the University of Colorado at Boulder. He is 

also Professor Emeritus of Atmospheric Science at Colorado State 

University. From 1999 to 2006, Dr. Pielke served as Colorado’s 

State Climatologist. He is a Fellow of the American Meteorological 

Society and the American Geophysical Union, where he also served 

on the Committee on Climate Change. Dr. Pielke has published 

over 370 papers in peer-reviewed journals, 55 chapters in books, 
14 

and co-edited nine books to date. Beginning in 1992, Dr. Pielke has 

served in a number of capacities related to the U.N.IPCC including 

as an expert reviewer. Dr. Pielke received his Ph.D. in meteorology 

from the Pennsylvania State University. 

We welcome you all and look forward to your testimony, and Dr. 

Tol, we will begin with you. 

TESTIMONY OF DR. RICHARD S.J. TOL, 

PROFESSOR OF ECONOMICS, UNIVERSITY OF SUSSEX 

Dr. TOL. Thank you, Mr. Chairman. It is an honor and pleasure 

to be here. 

An appropriate solution to any problem requires a good understanding of its mechanisms, its consequences and the consequences 

of any countermeasure. The climate problem is so complex that at 

the moment, only the United States can mount sufficient expertise 

to cover the entire issue. Other countries need international collaboration from a body like the Intergovernmental Panel on Climate Change. 

The common understanding of the issues is probably also helpful 

for the international climate negotiations. I therefore favor reform 

of the IPCC rather than its abolition. 

I will focus my remarks on Working Group II of the IPCC because I know that one best. Working Group II is on the impacts 

of climate change. Researchers tend to study those impacts because 

they are concerned about climate change. Academics who research 

climate change out of curiosity but find less than alarming things 

are ignored unless they rise to prominence, in which case they are 

harassed and smeared. 

People volunteer to work for the IPCC because they worry about 

climate change. Governments nominate academics to the IPCC but 

we should be clear that it is often the environment agencies that 

do the nominating. All this makes that the authors of the IPCC are 

selected on concern as well as on competence. This shows in the 

5th Assessment Report of Working Group II. The Summary for Policy Makers talks about trends in crop yields but missed the important trend of them all, which is technological change. It shows the 

impacts of climate change on agriculture, assuming that farmers 

will not adjust their practices in the face of changed circumstances. 

It shows that the most vulnerable country would pay some ten percent of its annual income towards coastal protection but omits that 

the average country would pay less than one-tenth of a percent. 

The SPM, the Summary for Policy Makers, emphasizes the 

health impacts of increased heat stress but downplays the health 

impacts of decreased cold stress. Therefore, the IPCC should investigate the attitudes of its authors and their academic performance 

and make sure that in the future they are more representative of 

their peers. If similar-minded people come together, they often reinforce each other’s prejudices. The IPCC should therefore deploy 

the methods developed in business, medicine and social psychology 

to guard against groupthink. 

Not all IPCC authors are equal. Some hold positions of power in 

key chapters. Others hold subordinate positions in irrelevant chapters. The IPCC leadership in the past has been very adept at putting troublesome—potentially troublesome authors in positions 
15 

where they cannot harm the cause. That practice must end. This 

is best done by making sure that leaders of the IPCC—the chairs, 

the vice chairs, the heads of technical support units—are balanced 

and open-minded. 

The IPCC releases a major report every six years or so. That is 

not frequent enough to keep abreast of a fast-moving literature. A 

report that is rare should make a big splash, and an ambitious 

team wants to make a bigger splash than last time—‘‘It is worse 

than we thought. We are all going to die an even more horrible 

death than before six years ago.’’ 

Launching a big report in one go also means that IPCC authors 

will compete with one another on whose chapter foresees the most 

terrible things. Therefore, I think that the IPCC should abandon 

its big reports and convert to journal-style assessments instead. 

In learned journals, the editor guarantees that every paper is reviewed by experts. IPCC editors do not approach referees. Rather, 

they hope that the right reviewers will show up. Large parts of the 

IPCC reports are therefore not reviewed at all or reviewed by people who are not field experts, and the IPCC should move to journalstyle reviews and editors. 

The IPCC is best scene as a natural monopoly. Monopolies 

should be broken up but natural monopolies where the costs of duplication are greater than the benefits of competition should be 

tightly regulated. The clients of the IPCC—the environment agencies of the world—are often also its regulators. It is time to end 

that cozy relationship. The climate problem is serious enough to deserve a serious international body to assess the state of knowledge. 

After the 4th Assessment Report, the InterAcademy Council suggested useful reforms. These were by and large ignored because the 

recommendations came after the preparations for the 5th Assessment Report had already started and because few countries supported IPCC reform. It should be said, though, that the 5th Assessment of IPCC Working Group II is a lot better than the 4th Assessment Report, and the IPCC does do useful things. The 5th Assessment Report shows, for instance, that the Stern Review overestimated the impacts of climate change and underestimated the impacts of climate policy. This undermines the justification of the 

two-degree target of the E.U., the U.N. and the current Administration of the United States. The 5th Assessment Report also 

shows double regulations, say, subsidies next to tradable permits, 

increases costs without further reducing emission. This conclusion 

was inadvertently dropped from the German translation, which is 

very unfortunate as double regulation is widespread in Germany. 

We need an organization that is not beholden to any government 

or any party to anchor climate change in reality as we currently 

understand it. A reformed IPCC can play that role. 

Thank you for your attention. 

[The prepared statement of Dr. Tol follows:] 
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Chairman SMITH. Thank you, Dr. Tol. 

Dr. Oppenheimer. 

TESTIMONY OF DR. MICHAEL OPPENHEIMER, 

ALBERT G. MILBANK PROFESSOR OF 

GEOSCIENCES AND INTERNATIONAL AFFAIRS, 

DEPARTMENT OF GEOSCIENCES, PRINCETON UNIVERSITY 

Dr. OPPENHEIMER. I would also like to thank you, Mr. Chairman, 

for convening these hearings because I think the subject is quite 

important, and for inviting me to testify. 

The views I am expressing are mine. They don’t adhere to IPCC 

and they don’t reflect Princeton University’s either. 

IPCC has served a critical function in providing governments 

regular assessments of the consensus view in the scientific community on the state of the science of climate change. I served as an 

author of every IPCC assessment report since the first one in 1990 

and also one special report. I am currently the coordinating lead 

author—a coordinating lead author of Chapter 19 for the Working 

Group II report. 

Although I found participating in IPCC to be personally and professionally rewarding, I have never hesitated to provide constructive public criticism of IPCC when I thought it was warranted. It 

is to IPCC’s credit that those who have been critical, even severely 

so, are invited to continue and even enhance their participation, 

and the smears that Richard talks about do not reflect IPCC practice nor the practice of most of the people involved in IPCC. 

As to author selection, names of potential authors are suggested 

by governments to IPCC. The United States has an open selection 

process that allows anyone to propose a name including their own. 

All names are forwarded by the U.S. government to IPCC, which 

evaluates the suggestions in light of professional expertise and the 

need for balance in terms of national representation, institutional 

affiliation and expertise. For example, most authors come from universities, governments and private research institutions but their 

affiliations range broadly in the past from ExxonMobil on the one 

hand to Greenpeace on the other. Several studies have compared 

projections of IPCC reports to actual outcomes in the real world, 

providing a basis to assess the claims of bias. Overall, there is a 

significant bias. It reflects the professional caution of scientists. 

Note that the assessments by the U.S. National Academy of 

Sciences and other major national academies around the world 

have arrived at judgments which are materially the same as 

IPCC’s. 

As to the review process, each report consists of chapters that go 

through three levels of comprehensive review, further reducing the 

potential for bias. I am not aware of any scientific review process 

which approaches IPCC’s in thoroughness. For example, over 

50,000 review comments were received from over 1,700 reviewers 

of the Working Group II report this time. Distinct from most peer 

review journals, the review process is fairly transparent with review comments and author responses actually posted for public 

consumption. A key role is played by the so-called review editors, 

who are independent experts who review the responses that the 
25 

chapters make to each and every of those review comments and assure that the reviews are responded to appropriately. 

As for the summary for policy makers, each working group report 

has a summary. It is intended for policy makers. Each SPM goes 

through two rounds of peer review. It is then reviewed at a plenary 

session with governments word by word. The objective of the approval process is to assure that it is clear and that it is accurate 

and that it is relevant to policy. The scientists who attend exercise 

an effective veto power over everything that goes into the SPM. 

Nothing can be inserted that is not scientifically accurate. No statement that the scientists who are present at the review session considered to be factually untrue and not representative of the science 

can survive. On the plus side, this process results in a clear document and, importantly, one that the governments accept as their 

own, including the United States and including under all Administrations. In this way, it is distinct from any other climate assessment performed by any another organization. 

On the negative side, in my view and the view of many of my 

colleagues, there have been occasions when government intervention by causing omissions have diluted IPCC findings. However, my 

belief is that the process on the whole has reflected what is in the 

reports in the underlying chapters and made them on the whole 

clearer and more understandable and even in some cases more accurate. 

My suggestions for improving the IPCC process are similar to 

Richard’s: more transparency, publish more frequent but much 

briefer reports, open the plenaries to the press so that shenanigans 

as occured in the recent plenary session of Working Group III are 

less likely to happen because the public will be watching, and experiment with other types of assessment processes like a formalized expert elicitation or the Team B approaches that the Defense 

Department uses. 

I found some of what Richard said to be a cartoon of the assessment process but we can talk about that in questions. 

In the end, the world needs an IPCC, IPCC needs to continually 

improve its performance to meet that need. Our ability to deal with 

the risk of climate change depends on it. 

Thank you. 

[The prepared statement of Dr. Oppenheimer follows:] 
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Chairman SMITH. Thank you, Dr. Oppenheimer. 

Dr. Botkin. 

TESTIMONY OF DR. DANIEL BOTKIN, 

PROFESSOR EMERITUS, 

DEPARTMENT OF ECOLOGY, EVOLUTION, 

AND MARINE BIOLOGY, 

UNIVERSITY OF CALIFORNIA, SANTA BARBARA 

Dr. BOTKIN. I want to thank you also, Chairman Smith, for having me speak here. I think it is very—— 

Chairman SMITH. Dr. Botkin, press the—— 

Dr. BOTKIN. Okay. I want to thank you also, Chairman Smith, 

for inviting me to speak. I think this is a very important topic, and 

I am glad to be here. 

Since 1968, I have published research on the possibility of a 

human-induced global warming and its potential human and ecological effects. I have spent my career trying to help conserve our 

environment and its great diversity of species, attempting to maintain an objective, intellectually honest approach in the best tradition of scientific endeavor. I have been dismayed and disappointed 

in recent years that this subject has been converted into a political 

and ideological debate. I have colleagues on both sides of the debate, and believe we should work together as scientists instead of 

arguing divisively about preconceived, emotionally based positions. 

I was an expert review of both the IPCC and the White House 

National Climate Assessment, and I want to state up front that we 

have been living through a warming trend driven by a variety of 

influences. However, it is my view that this is not unusual, and 

contrary to the characterizations by the two reports, these environmental changes are not apocalyptic nor irreversible. I hope my testifying here will help lead to a calmer, more rational approach to 

dealing with climate change and with other major environmental 

problems. The two reports do not promote the kind of rational discussion we should be having. I would like to tell you why. 

My biggest concern is that the IPCC 2014 and the White House 

Climate Change Assessment present a number of speculative, 

sometimes incomplete conclusions embedded in language that gives 

the more scientific heft than they deserve. The reports are scientific-sounding rather than based on clearly settled facts or admitting their lack. Established facts about global environment exist 

less often in science than laymen usually think. 

The two reports assume and argue that the climate warming 

forecast by the global climate models is happening and will continue to happen and grow worse. Currently, these predictions are 

way off the reality. There is an implicit assumption in both reports 

that nature is in steady state, that all change is negative and undesirable for all life including people. This is the opposite of the reality. Environment has always changed. Living things have had to 

adapt to these changes and many require change. The IPCC report 

makes repeated use of the term ‘‘irreversible changes.’’ A species 

going extinct is irreversible but little else about the environment 

is irreversible. 
36 

The report gives the impression that living things are fragile and 

rigid, unable to deal with change. The opposite is the case. Life is 

persistent, adaptable, adjustable. In particularly, the IPCC report 

for policy makers repeats the assertion of previous IPCC reports 

that large fraction of species face increased extinction risk. Overwhelming evidence contradicts this assertion. Models making these 

forecasts use incorrect assumptions, leading to overestimates of the 

extinction risks. Surprisingly few species became extinct during the 

past 2–1/2 million years, a period encompassing ice ages and warm 

periods. 

The extreme overemphasis on human-induced global warming 

has taken our attention away from many environmental issues that 

used to be front and center but have been pretty much ignored in 

the 21st century and demand our attention. 

Some of the report’s conclusions are the opposite of those given 

in articles cited in defense of those conclusions. For example, the 

IPCC Terrestrial Ecosystem Report states that seven of 19 subpopulations of the polar bar are declining in number, citing in support of this an article by Vongraven and Richardson, but these authors state the contrary, that the ‘‘decline is an illusion.’’ In addition, the White House Climate Assessment includes a table of 30 

different ecological effects resulting from climate change, a striking 

list of impacts. However, I reviewed the studies cited to support 

this table and found that not a single one of these 30 is supported 

by a legitimate impact and analyzed from human-induced global 

warming of direct observations. 

Some conclusions contradict and are ignorant of the best statistically valid observations. For example, the IPCC terrestrial ecosystem report states that terrestrial and freshwater ecosystems 

have sequestered about a quarter of the carbon dioxide emitted in 

the atmosphere by human activities in the past three decades— 

high confidence. Having done the first statistically valid estimates 

of carbon storage and uptake for any large areas of the earth, I can 

tell you that estimates of carbon uptake by vegetation used by 

IPCC are not statistically valid and overestimate carbon storage 

and uptake by as much as 300 percent. 

The IPCC report uses the term ‘‘climate change’’ with two meanings: natural and human induced. These are not distinguished in 

the text and therefore confusion. If a statement is assumed to be 

about natural change, then it is a truism, something people have 

always known and experienced. If the meaning is taken to be 

human caused, then the available data do not support the statements. 

The issues I brought up in my reviews of the reports have not 

been addressed in their final versions. With the National Climate 

Assessment, I stated that the executive summary is a political 

statement, not a scientific statement. It is filled with 

misstatements contradicted by well-established and well-known scientific papers. 

Climate has always affected people and all life on earth, so it 

isn’t new to say it is already affecting the American people. This 

is just a political statement. It is inappropriate to use short-term 

changes in weather as an indication one way or another about persistent climate change. 
37 

Thank you. 

[The prepared statement of Dr. Botkin follows:] 
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Chairman SMITH. Thank you, Dr. Botkin. 

Dr. Pielke. 

TESTIMONY OF DR. ROGER PIELKE SR., 

SENIOR RESEARCH SCIENTIST, 

COOPERATIVE INSTITUTE FOR RESEARCH 

IN ENVIRONMENTAL SCIENCES, 

AND PROFESSOR EMERITUS OF ATMOSPHERIC SCIENCE, 

COLORADO STATE UNIVERSITY 

Dr. PIELKE. Okay. Mr. Chairman, thank you very much for inviting me to speak today. 

I am going to focus on specifically one issue. The IPCC Working 

Group 1 and National Climate Assessment reports have not adequately tested the skill of the client models to predict changes in 

regional climate statistics on multiple decadal timescales when 

tested by using the observed human activities, including fossil fuel 

emissions over the last several decades. Indeed, even when these 

models are run using observed initial conditions on decadal time 

periods, they have at best only very limited regional skill. 

The parts of the reports based on these model results is misleading the impact community and policymakers on the confidence 

that can be placed on regional climate impacts in the coming decades. This issue is independent of how important one has concluded is the addition of CO2 for the atmosphere. Model projection 

skills should be a concern and addressed regardless of one’s views 

on mitigation and adaptation. 

So the summary of my major points: The 2013 IPCC report and 

the 2014 U.S. National Climate Assessment present a set of projections from local and downscaled regional climate models as the 

basis for projecting future societal and environmental impacts, and 

thus is offered as a guide to the future for decision-makers. 

However, these projections have not been robustly shown to be 

accurate guides to the future. In fact, we aren’t able to adequately 

quantify their reliability. The IPCC and NCA did not adequately 

discuss the skill run in hindcast predictions over the last several 

decades when the human activity, including fossil fuel emissions, 

are actually known. 

Except for limited exceptions, the models cannot protect in 

hindcast runs over the last several decades the temporal evolution 

of major atmospheric circulation features over multi-decadal time 

periods, and these include, for example, the El Nin ̃ o, the La Nin ̃ a, 

the Pacific Decadal Oscillation, and the North Atlantic Oscillation. 

It is these major factors which determine which regions have 

drought, flood, tropical cyclone tracks, and other societally and environmentally important weather events. A global average is really 

not that useful of a metric for these particular very important 

weather phenomena. 

The models have an even greater challenge in accurately predicting changes in statistics of these major atmospheric circulation 

features over multi-decadal timescales. 

The IPCC and the National Climate Assessment should have reported such model limitations that were available to them in the 

peer-reviewed literature. And I document a whole series of these 
54 

papers in the peer-reviewed literature in my written testimony. 

Without this information, decision-makers who face decisions at the 

regional and local scale will have a false sense of certainty about 

the unfolding climate future. 

Thank you, Mr. Chairman. 

[The prepared statement of Dr. Pielke follows:] 
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Chairman SMITH. Thank you, Dr. Pielke. I will recognize myself 

for questions and then we will move on to the Ranking Member. 

Now, Dr. Tol, you refused to sign onto the Summary for Policymakers for Working Group 2 for the most recent IPCC report. You 

were quoted as saying, ‘‘There are a number of statements that are 

widely cited that are just not correct.’’ What would be some examples of those kinds of statements? 

Dr. TOL. I mentioned a couple of them already. What the SPM 

says about agriculture and the impacts of agriculture I just don’t 

think reflect the literature or would be accurate. What they say is 

that, because of climate change, crop yields would fall by about two 

percent per decade. It is probably true. They also say the population will probably grow by 30 percent over the same time period 

so it is probably true as well. But they admit that because of technological change, crop yields have been going up, so the IPCC sort 

of paints this picture of eminent famine which I don’t think is supported by any evidence whatsoever. 

Chairman SMITH. Okay. Thank you, Dr. Tol. 

Dr. Oppenheimer, I don’t have a question for you but I wanted 

to thank you for your suggestions as to how the IPCC could be 

more open and transparent and I hope they will heed your good 

suggestions. 

Dr. OPPENHEIMER. Thank you. 

Chairman SMITH. Dr. Botkin, you made some head-turning statements here. You mentioned the White House list of 30 impacts, 

that not one was true. You said the polar bear population, statements about it being declining, was the opposite; they were increasing. You said the Administration or the IPCC doesn’t distinguish 

between natural and human-caused climate change and you said it 

was largely a political statement. I don’t know what more to ask 

you. That covers it pretty well. But one question I had for you was 

the Administration’s claim that extreme weather is directly connected by human-induced climate change. What do you think about 

their statements in that regard? 

Dr. BOTKIN. When I was a graduate student, I read Bryson, one 

of the great men of climatology, and at that time it was 1960. He 

told me that the climate had been cooling since 1940, and if 

present trends continued, this was going to lead to a new Ice Age. 

And I was in a position to be on the right newspaper article, so I 

went back to him with that as a lead story because that was a 

great lead, and he thought about it and thought about it and he 

said, you know, Dan, this is just a 20-year weather change. We 

can’t make that kind of extrapolation. 

And then in the 1980s I worked closely with Steve Schneider 

who, along with Jim Hansen, did a lot to promote our concern with 

global warming. And Steve and I spoke on the same platforms and 

often discussed things and he always made the point that you cannot use short-term weather, meaning decadal even, weather 

changes has an index of climate change. 

So to assert, as the White House report does right at the beginning, that current weather changes are due to climate changes, it 

violates one of the basic principles of how I understand you approach climatology. 
68 

And also, there is analyses that show that the changes are not 

out of the ordinary. 

Chairman SMITH. Okay. Thank you, Dr. Botkin. 

And, Dr. Pielke, I want to put a PowerPoint up on the screen 

here and ask you about it. This shows, I believe, that even if the 

United States eliminated all emissions entirely, it would have almost no impact on global temperatures. But I would like for you 

to address that. I mean no one thinks that is going to happen, but 

what if we were to cut emissions in half? Is that going to have any 

discernible, any appreciable effect on global temperatures or not? 

If you can kind of put this in perspective. 

And, by the way, as I mentioned in my opening statement of 

course the United States has actually cut emissions over the last 

several years, I think nine percent over the last four years. We are 

going that direction. But even if we went further, even if we cut 

emissions even more, is that going to have any impact? 

Dr. PIELKE. Well, that is a really good question. I think the way 

to answer this question is to use those models that the IPCC uses 

as process studies, not as predictions but look at sensitivities, and 

I think that is the kind of numbers that one produces when you 

insert that in the models. 

Chairman SMITH. And just so that I am clear, so if the United 

States were to either eliminate emissions or cut them in half or 

dramatically reduce them, as the Administration proposes, it is not 

going to have any discernible impact on global temperatures in the 

near future and perhaps even long-term? 

Dr. PIELKE. That is true by any country of course that—— 

Chairman SMITH. Yes. 

Dr. PIELKE. —if one would do that, yes. 

Chairman SMITH. Okay. What about other countries? If other 

countries follow the United States, they will even cut their emissions, is that going to have any particular impact? 

Dr. PIELKE. Well, it would have more of an impact of course. And 

again, the way to quantify this is with—to use the models as these 

process tools. And I think the figure that you have up there illustrates that—— 

Chairman SMITH. Okay. 

Dr. PIELKE. —you have to have a huge reduction in order to get 

a large impact. 

Chairman SMITH. And again, to make my point, if the United 

States were to eliminate all emissions, the projection is that by 

2050 it would only reduce global temperatures by 0.08 percent. Do 

you agree with that? 

Dr. PIELKE. Well, I would accept your results because I mean I 

think you are presenting results from the models and that—— 

Chairman SMITH. Right. 

Dr. PIELKE. —I think that is the kind of sensitivities they show. 

Chairman SMITH. Okay. Thank you, Dr. Pielke. That concludes 

my questions. 

And the Ranking Member, Ms. Johnson, is recognized for hers. 

Ms. JOHNSON. Thank you very much. 

Dr. Oppenheimer, some of the testimony from the other panelists 

today seems to suggest that minority views or opinions are not adequately considered as part of the IPCC process. However, in your 
69 

testimony you state that, unlike the situation with many other institutions, those who have been critical, even severely so, are invited to continue and even enhance their engagement in the process. Can you please describe the inclusive nature of the IPCC process and how lead authors deal with differences in opinion? 

And secondly, also, it is my understanding that comments on the 

report can be submitted from any scientist or expert who chooses 

to do so and that every comment is individually considered. Can 

you please describe the review process and the role of review editors in ensuring a transparent process? 

Dr. OPPENHEIMER. Thank you. Yes, I can. With regard to the 

first question, differences of opinion, I will give you an anecdote. 

During the last assessment, the fourth assessment, there were significant differences of opinion about how to represent what was 

going on in the Greenland and Antarctica ice sheets. Both ice 

sheets known to be losing ice and adding to sea level. They now 

account for about 1/3 of sea level rise that we are seeing today. And 

the question was what models should be used in projecting that 

into the future? There was disagreement among the authors, disagreement across working groups, and as a result, authors met 

during meetings. There were about four author meetings for each 

working group, and they met on the side in between meetings in 

order to work out differences and they exchanged a lot of email. 

And the final language, although it wasn’t adequate in my view, 

did reflect the fact that there were differences of opinion on this 

issue. I think IPCC can do a much better job of showing the full 

spectrum of opinion on issues by the authors and I hope it will do 

so in the future. 

As far as the review procedure, it is actually very painful. As I 

said, 50,000 comments on 30 chapters, that is an average of more 

than 1,000 per chapter, and we have to address every single one 

of them. And if we fail to do so, we have these independent scientists on our neck insisting that we go back and they actually can 

hold up the completion of a chapter until comments are adequately 

addressed. 

Ms. JOHNSON. Thank you. In Dr. Botkin’s testimony he characterizes IPCC process as a very large number of people doing long 

reviews of the scientific literature and cautions against using, as he 

described it, a crowdsourcing model of information-sharing. Dr. Tol 

also suggests that IPCC process is vulnerable to this kind of 

groupthink. It seems to me that consensus does not equal 

groupthink and that this is a mischaracterization of the process 

and the resulting assessments. What do you think of these claims 

by the two witnesses? 

Dr. OPPENHEIMER. First of all, I would want to say there were 

a number of particular scientific claims by both of them that were 

inaccurate, but there is no room to actually talk about all the inaccuracies right now so let me go on and answer your question. 

I think groupthink is a real possibility. It has been shown to 

occur when you have groups of people together. And I think occasionally IPCC is the victim of the scientific tendency to all be cautious at the same time, and we need to find ways to get over that. 

And the suggestion that Richard made and that I made of having 
70 

alternative teams of scientists within IPCC looking at the same 

question I think would be an improvement. 

But given the current structure of IPCC, I think by and large the 

review process helps push in the right direction so that although 

I can’t say that there isn’t any groupthink, I also think it is minimized but I think the process can be improved further. 

Ms. JOHNSON. Now, Dr. Tol also suggests that leadership of 

IPCC intentionally marginalizes authors that they view as troublesome by placing them in positions where they cannot ‘‘harm the 

cause.’’ As I understand it, the United States has a very open selection process in which anyone can submit their name and all of 

those names are forwarded to the IPCC. Can you please describe 

the—how IPCC selects the authors for the assessment? 

Dr. OPPENHEIMER. Well, that comment puzzled me because Richard, who is a very smart guy, is also one of the biggest troublemakers among authors in that he says what he thinks, which is 

great, and he hasn’t been marginalized. He was made the cohead 

of a chapter. He has done before and he did a great job. So, I don’t 

know what this cabal is about frankly. 

Ms. JOHNSON. Thank you. My time is up. 

Chairman SMITH. Thank you, Ms. Johnson. 

The gentleman from California, Mr. Rohrabacher, is recognized. 

Mr. ROHRABACHER. Thank you very much. 

First, Dr. Oppenheimer, I don’t mean this as—don’t take—I 

guess you will take it personally or not. Okay. Let me just state 

right out one of the things that has disturbed me most about the 

debate on global warming over the years has been the tendency of 

people who are pushing this concept to dismiss those who disagree 

with them. And I mean I remember in this Committee and I remember in other Committees listening to the words ‘‘case closed,’’ 

which was basically trying to restrict an honest discussion rather 

than open an honest discussion. 

And just today you, for example, just in passing noted that you 

felt your colleague, his views are like cartoons. And I am sorry, 

that doesn’t reflect a good thing to me. That is a dismissal and you 

just mentioned you didn’t have time enough to go through where 

you disagree. Most people when they disagree with someone at 

least encapsulate it in a time period that they have got, whether 

it is 15 seconds or 10 seconds where we disagree on this rather 

than dismiss. And I think that probably that is the thing that gets 

me the angriest about this whole issue of global warming is that 

one side dismisses the other. Please feel free to comment. 

Dr. OPPENHEIMER. The cartoon remark was aimed at only one 

sentence that Richard spoke, which is that somehow everybody is 

out-racing the other one to make the most extreme assessment so 

that their chapter will get the headline. I just don’t agree with 

that. I think if it goes on in anybody’s head, it is a cartoon of the 

process and it bears no relation to how people behave. 

As far as the scientific facts being right or wrong, I try very hard 

to let everybody have their say on scientific facts and then they can 

be discussed as facts. I think everyone should be listened to. But 

in the end, governments have to act on evidence that the large majority of the scientific community believes while not dismissing the 
71 

fringes, listening to them, weighing them, and making decisions. So 

that is my view and I try to behave accordingly. 

Mr. ROHRABACHER. All right. Well, again, which leads one to believe that the other people on their outside views are fringes. And 

again, it is an attitude that I find overwhelming among those people who are pushing the global warming or believe in that theory. 

Let me just go to some of the specifics on it. Let me just ask the 

panel if you can give me yes or no. Is this 97 percent of all scientists believe that global warming is a result—and that global climate change is a result of human activity? Is that accurate or inaccurate from what you see from other scientists and from what you 

know? 

Dr. TOL. I guess this question is directed to me. 

First, let me say that I did not take any offense with the cartoon 

statement by Dr. Oppenheimer. I have five minutes so what can 

you do other than draw a few—— 

Mr. ROHRABACHER. Oh, believe me, if I took offense at all the 

things they said about me, I would be offended all the time. 

Dr. TOL. No, exactly. 

The 97 percent estimate is bandied about by basically everybody. 

I had a close look at what this study really did and as far as I 

know, as far as I can see, this estimate just crumbles when you 

touch it. None of the statements in the papers are supported by 

any data that is actually in the paper, so unfortunately—I mean 

it is pretty clear that most of the science agrees that climate 

change is real and most likely human-made, but is—97 percent is 

essentially pulled from thin air. It is not based on any credible research whatsoever. 

Mr. ROHRABACHER. I only have a couple more seconds in my time 

period. Would you say you agree with that assessment, the 97 percent is inaccurate? 

Dr. OPPENHEIMER. I actually haven’t read the paper, although I 

am familiar with the argument about it, but my view is similar to 

Richard’s in the other respects, namely the lion’s share of the scientific community believes that the Earth is warming—— 

Mr. ROHRABACHER. No—— 

Dr. OPPENHEIMER. —and that most of the warming is humanmade. 

Mr. ROHRABACHER. But I will have to also point out that one of 

the other things that upsets me in the debate is that people who 

are arguing the case for global warming always refuse to answer 

a specific question when they know that it will not bolster the argument for global warming. 

Dr. OPPENHEIMER. You want me to comment on something I 

haven’t read? 

Mr. ROHRABACHER. Well, I wasn’t asking about something that 

you read. This has not been just published in one article. This 97 

percent figure has been repeated over and over and over again by 

such a wide variety of people that that is—I am asking about—— 

Dr. OPPENHEIMER. That is because there have been many scientific articles that have studied what scientists have said and 

have come to conclusions which are similar. Whether the 97 percent is defensible or not, I really don’t know. 
72 

Dr. BOTKIN. I would like to break in here if I may. What a scientist finds out is science. What a scientist says is opinion and 

science is not a consensus activity. Science is innovative and invention and discovery. 

Now, I have spent my life looking at facts and analyzing facts. 

I have been concerned about global warming since 1968 and in the 

1980s it looked like the weight of evidence went towards humaninduced significant—to a significant extent, and since then, it has 

moved against it. But for me it doesn’t matter—it isn’t the point. 

It is the wrong point about how many people approve. That is not 

science. What it is is the facts, the interpretation of the facts, and 

their analysis. So it is the wrong metric. 

Chairman SMITH. Okay. Thank you, Mr. Rohrabacher. 

This might be a good time for me, without objection, to put into 

the record an article from the Wall Street Journal three days ago, 

May 26. The headline is ‘‘The Myth of the Climate Change 97 Percent.’’ So without objection, that will be made a part of the record. 

[The information appears in Appendix II] 

Chairman SMITH. The gentlewoman from Oregon, Ms. Bonamici, 

is recognized for her questions. 

Ms. BONAMICI. Thank you very much, Mr. Chairman. Thank you 

to all the witnesses. 

Dr. Oppenheimer, in written testimony Dr. Pielke asserts that 

the climate models used by the IPCC for projecting future societal 

and environmental impacts from climate change may not be reliable and that by not accurately reporting the limitations of the climate models, the IPCC is giving policymakers a false sense of certainty about the climate future. It is my understanding that the climate models have improved since the previous assessment, so will 

you address how important our model projection is to our understanding of the climate issue and can you also discuss the current 

state of climate modeling? And I do have another couple of questions as well. 

Dr. OPPENHEIMER. Well, first of all, there are endless, and I 

mean endless and painful discussions in the underlying chapters 

about the uncertainties, which are mentioned in the Summary for 

Policymakers. Everybody is aware that projecting the future is a 

fraught activity, that it can be—we can be highly inaccurate, but 

we have tools and we use them as best we can. 

The fact of the matter is, though, that if you took the climate 

models and threw them away and never referred to them, there 

would be adequate evidence that Earth is changing, that the climate is warming, that much of that change is due to human activity, and that in the past such changes have wrought very substantial impacts which would be quite threatening to society if they 

were left unabated. That evidence comes from not only observations of climate change and change to ecosystems that those climate changes are causing but also a very deep understanding of 

what are called paleo climates, climates of 1,000, 10,000, 1 million 

years ago. 

Even without the evidence from models, we know that over time 

large warming has been generally associated with changes in carbon dioxide levels in the atmosphere. Those in the past were natural changes. The current changes are by and large faster and the 
73 

carbon dioxide levels have already reached a level which is above 

any for many million years. 

Ms. BONAMICI. And thank you. And I do want to also ask, you 

mentioned something about—— 

Dr. BOTKIN. Can I break in and make a comment? 

Ms. BONAMICI. I need to finish with my time, Dr. Botkin—— 

Dr. BOTKIN. Okay. But I do—— 

Ms. BONAMICI. —I have got another question—— 

Dr. BOTKIN. —want to disagree because I—— 

Ms. BONAMICI. Well, somebody else can ask you. I wanted to ask 

Dr. Oppenheimer again. 

As I understand that the IPCC has fairly robust guidelines on 

how authors are to treat uncertainty as part of the assessment. So 

oftentimes in this committee and in Congress we talk about uncertainty and it is used sometimes as a tool to discredit in the field 

of climate science as a whole as if any scientific theory that is less 

than 100 percent certain should be discredited. So what role does 

uncertainty play? How should it be considered in decision-making 

and considering the current climate conditions and the impacts of 

global climate change and ocean acidification that I know many of 

my constituents are already beginning to experience? Can you talk 

about the potential risks of inaction if we were to wait for 100 percent consensus or certainty on climate change? 

Dr. OPPENHEIMER. Well, on the last point we know that the lifetime of carbon dioxide in the atmosphere, unless some genius invents a way to cost-effectively remove it from the atmosphere, is 

very long, ranging from hundreds of years to even longer, and 

about 20 percent of the carbon dioxide that is in the atmosphere 

today due to human activity will still be there 1,000 years from 

now warming the climate. So there is an irreversibility in the system. Actions or lack thereof today make a commitment to what the 

climate will look like 10, 50, 100, 1,000 years from now. 

Ms. BONAMICI. And, Dr. Oppenheimer, you suggest in your testimony that there is a way to improve transparency of the IPCC 

process and that is to publish a record of significant divergent 

viewpoints. Dr. Tol testified about outside challengers and that 

their advice is ignored. That is interesting because if there is an 

outside challenger, there—just because their view is not accepted 

does not mean they were ignored. They are considered and maybe 

not agreed with. But can you talk about your rationale for this suggestion to improve the transparency by publishing that record of divergent viewpoints and how would that contribute to the assessment as a whole? 

Dr. OPPENHEIMER. Yes. It would be healthy for everyone if everyone could measure who was saying what and what their view was 

and how it diverged from what was reported as the main view or 

the consensus and people could make their own judgments. You as 

our leaders could make your own judgments about who to listen to 

and whose view made sense and why and why not. Right now it 

is too much—there is too much going on behind the curtain and I 

would like to lift that curtain and make it more public. 

I want make one comment on the irreversibility question. Dr. 

Botkin says nothing is effectively irreversible. Well, if you lose 

most of the ice from the West Antarctic ice sheet and it raises sea 
74 

level, that is irreversible on a timescale of 10,000 years. That is irreversible enough for me. 

Ms. BONAMICI. Thank you. And—— 

Dr. BOTKIN. That is not actually irreversible. 

Ms. BONAMICI. And I only have five minutes and my time is expired. I yield back, Mr. Chairman. 

Mr. SCHWEIKERT. [Presiding] Thank you. 

Representative Neugebauer. 

Mr. NEUGEBAUER. Thank you, Mr. Chairman. And thank you for 

holding this hearing. 

Dr. Pielke, several years ago I had an opportunity with some 

other Science Committee members to go to the South Pole and obviously, as many of you know, they are doing a lot of research on 

climate change in that laboratory down there, but one of the scientists that was sitting there showed me a very long graph of the 

temperatures dating back thousands of years and forecasting thousands of years. So that was my kind of first introduction to the 

models. And so I asked him, well, how long have we been recording 

data? And so this very long graph, and actually, on that graph if 

you looked at the time frame where we were actually recording 

have data, it was a very small part of that. And so his whole 

premise was based on these models. And in your testimony, it includes an image of 120 I think model runs, including those used 

by the IPCC and White House climate change for global temperature from 1975 to 2025. For the period of, say, 2000 to present, how 

many of these models have been in the ballpark as projected to the 

actual? 

Dr. PIELKE. Well, it is a really good question. In terms of the 

global average, very few of them, but that is actually not even the 

complete question. The question is how well can they do on the 

major weather events? And in my written testimony I document a 

series of papers, one of them by the one of the authors of the National Climate Assessment that says these models can’t be used for 

precipitation. They are not that good. So the reality of it is it is 

worse than that. Even if they could replicate the global average in 

the last 14 years or so, which they haven’t been able to do very 

well, they have not been able to predict the major weather features 

that affect drought and floods. 

And I think Michael’s point was actually a good one. We don’t 

need the models probably for that. The models I think are misleading us and I think we need to recognize that. They also may 

be misleading us in terms of attribution so it is a tougher problem, 

but we do have some information. We know that CO2 is increasing. 

We know that land use is changing. We know we are putting more 

nitrogen on the Earth’s surface. We know it is a very wide range 

of issues we face and I think that is how we should approach the 

problem is a broader perspective, and the models unfortunately, 

which were very heavily relied on by both the IPCC and the National Climate Assessment, I think are misleading everyone in 

terms of the confidence we have of what is going to happen in the 

future. 

Mr. NEUGEBAUER. So I don’t want to put words in your mouth, 

but the models are being used I think to drive a lot of policy. Would 

you agree? 
75 

Dr. PIELKE. I 100 percent agree with that, yes. 

Mr. NEUGEBAUER. And so if the models aren’t correct and as you 

say and Dr. Oppenheimer said, that possibly the models are irrelevant, then should we start disregarding that? And what is a better 

metric for climate policy to be made on if not the models? 

Dr. PIELKE. Well I—first of all, in terms of what I would recommended is that we try to develop our society so it is more resilient to weather events that occurred in the past with today’s infrastructure or maybe worst case scenarios events or maybe paleo 

record events. Try to make our society more vulnerable—more resilient to them so we are not as vulnerable. That way we can protect ourselves regardless to the extent we are altering the climate 

in the future. To me that is a much more inclusive approach. It 

should be bipartisan and everyone would benefit from that. But instead, we are relying on these models to say this is what it will be 

20, 30, 40 years from now making policy based on that when the 

models clearly are not working. 

Dr. BOTKIN. Could I add a point here? 

Mr. NEUGEBAUER. Sure. 

Dr. BOTKIN. Since my field is ecology, ecosystems and species, 

where we learn a lot is from the paleo record, the reconstructions 

of climate and the history of extinctions and persistence of species, 

and that is where I believe the key is if we are going to look on 

effects. Dr. Oppenheimer said it was clear that there were damaging ecosystem effects, but there are changes, just as there have 

been changes in the past. 

And as I mentioned before, we look carefully and in the last 2– 

1/2 million years, in spite of widespread climate changes of many 

kinds, very few species went extinct, so it is that kind of information we need to use. 

Mr. NEUGEBAUER. I think just one last question for the whole 

panel. One of the conversations in the past, speaking of the past, 

has the climate on Earth been warmer and colder or has it always 

been one trend? Have there been periods where it has been colder, 

then warmer, then colder again? 

Dr. OPPENHEIMER. It has been colder, it has been warmer. What 

is distinct this time is that there is an extended warming which 

threatens, if we keep the emissions up, to go on indefinitely at a 

rate which is unprecedented over an extended period, and certainly 

in the history of civilization. The climate has been very stable over 

the last 10,000 years or so. We threaten to bring that period to an 

end through our emissions of the greenhouse gases. 

Dr. BOTKIN. That is not correct. There has been a little Ice Age, 

there has been the warming. 

Mr. SCHWEIKERT. Forgive me. For everyone on the panel and everyone here, because this is a back-and-forth, I will beg of you that 

when we have things we want to share, have the Members reach 

out to you. 

Dr. BOTKIN. Okay. 

Mr. SCHWEIKERT. Mr. Neugebauer, anything else? 

Mr. NEUGEBAUER. My time is expired. 

Mr. SCHWEIKERT. It is. Thank you, Mr. Neugebauer. 

Mr. Swalwell. 

Mr. SWALWELL. Thank you, Chairman. 
76 

And, Dr. Tol, you served as a convening lead author in Working 

Group 2. Is that right? 

Dr. TOL. Correct. 

Mr. SWALWELL. Who nominated you to that? 

Dr. TOL. The Irish Government. 

Mr. SWALWELL. And you noted that it is often the case that environmental agencies do the nominating but in your case it was not 

an environmental agency, is that right? 

Dr. TOL. It was the Environmental Protection Agency of Ireland. 

Mr. SWALWELL. But it was ultimately the government’s appointment? 

Dr. TOL. Yes. 

Mr. SWALWELL. And it is correct that there were 308 total convening authors in Working Group 2, is that right? 

Dr. TOL. 308 authors, yes. 

Mr. SWALWELL. You were one of the 308? 

Dr. TOL. Correct. 

Mr. SWALWELL. How many scientists in the world at the time 

that you were appointed to that working group were working in 

this area of science? Can you estimate? 

Dr. TOL. Tens of thousands. 

Mr. SWALWELL. Tens of thousands. So you were in a working 

group, one of 308, in an area with tens of thousands of scientists? 

Dr. TOL. Yes. 

Mr. SWALWELL. And it is your position that competent people 

have been excluded because their views do not reflect the views of 

government from the working group? 

Dr. TOL. That is correct. 

Mr. SWALWELL. Yet you have views that are different from the 

working group, right? 

Dr. TOL. Correct. 

Mr. SWALWELL. And Dr. Oppenheimer pointed out that many 

times you are a loud voice against the views of the majority, is that 

right? 

Dr. TOL. That is also correct. 

Mr. SWALWELL. Yet you were still included in the working group? 

Dr. TOL. Yes. I would argue that I am an exception. Yes. 

Mr. SWALWELL. Okay. And you describe in your testimony mishaps in the process? Yes? 

Dr. TOL. Yes. 

Mr. SWALWELL. And you stated that you are worried about 

groupthink, is that right? 

Dr. TOL. Correct. 

Mr. SWALWELL. And you also said that there should be protections against groupthink, is that right? 

Dr. TOL. Correct. 

Mr. SWALWELL. So you had a lot of concerns about IPCC, safe to 

say? 

Dr. TOL. Yes. Yes. 

Mr. SWALWELL. And you were one of the few scientists in the 

whole world, one of 308, who had the privilege and honor of being 

at the table as these decisions were being made. That is safe to 

say, right? 

Dr. TOL. Yes. 
77 

Mr. SWALWELL. But instead of fighting within the IPCC to be a 

force for reform and fight against groupthink and be a force for the 

minority views, you chose to quit the working group, is that right? 

Dr. TOL. No. I am still a convening lead author of chapter 10 of 

Working Group 2. I quit the drafting team of the Summary for Policymakers. 

Mr. SWALWELL. Okay. So you used in your words ‘‘step down’’ 

from the summary of policymakers team for Working Group 2? 

Dr. TOL. Yes. 

Mr. SWALWELL. Were there any other scientists in Working 

Group 2 that quit? 

Dr. TOL. I don’t think so. 

Mr. SWALWELL. You were the only one? 

Dr. TOL. Yes. 

Mr. SWALWELL. You would agree, Dr. Tol, with the following 

statement: ‘‘Climate change is occurring and most likely caused by 

humans’’? 

Dr. TOL. Correct. 

Mr. SWALWELL. And in fact you wrote in June 2013, ‘‘It is well 

known that most papers and most authors in the climate literature 

support the hypothesis that anthropogenic climate change, that 

most papers and most authors in the climate literature support the 

hypothesis of anthropogenic climate change. It does not matter, it 

does not matter whether the exact number is 90 percent or 99.9 

percent.’’ Is that right? 

Dr. TOL. I can’t recall that exact quote by would agree with that 

statement, yeah. 

Mr. SWALWELL. Okay. Thank you, Dr. Tol. 

And, Dr. Pielke, you stated that it would make no difference if 

we reduced our carbon emissions by 50 percent, is that correct? 

You told—— 

Dr. PIELKE. No, I didn’t say it would take no difference. It just 

makes more difference if you reduce it 50 percent than if you reduce a 25 percent. No. 

Mr. SWALWELL. Do you think we should double our carbon emissions? Would that make any difference? 

Dr. PIELKE. You would have an effect. You would have more reinforcing if you increase in CO2. I mean it is—if you use the models. 

The models are the tools that you use to assess that and they 

would say if you put more CO2 in there, you get more positive reinforcing. You take it out, you get less reinforcing. I think the problem is that you are confusing—when we talk about anthropogenic 

climate forcing, people think fossil fuels. Fossil fuels is one of them. 

There is a whole range of them. There was an Academy report back 

in 2005 that talked about broadening out this perspective. We have 

to look at these other things. There is a black carbon, there is land 

use change, there is other aerosol effects. It is a more complicated 

problem, and I think one of the problems of the National Climate 

Assessment is they focused on fossil fuels. So that is what you are 

asking the question about but really our impact on the environment is much broader than that. 

Mr. SWALWELL. Would we be healthier and better off if we doubled our carbon emissions or reduced them by 50 percent? 
78 

Dr. PIELKE. If we are healthier or not? I don’t know about that 

question, but in terms of how our climate impact is, you double the 

CO2, you have more of a climate impact that you have half. But 

healthy is not the right question because CO2 is not a pollutant 

like a traditional pollutant. 

Mr. SWALWELL. Would you prefer to live in a world that doubled 

its carbon emissions or one that cut them in half? 

Dr. PIELKE. Everything else being equal, it—that is an interesting question actually. 

Mr. SWALWELL. That is why we brought you here. 

Dr. PIELKE. Well, that is an interesting question but, no, I was 

coming here to talk about the science and some of the science 

issues. That is a question—that is a broad-range question about 

what is the benefits and costs of doubling or decreasing CO2. Obviously, if we have less emissions into the atmosphere, it is a positive 

thing. That includes aerosols, that includes nitrogen oxide, sulfur 

dioxide, et cetera. All of that is beneficial. If we don’t put anything 

in the atmosphere, if we don’t put anything in the ocean, but the 

reality of it is we have to try to optimize that. And by—I think we 

need a broad-based approach to this problem and not focusing on 

just one issue, which is what the question you are asking is. 

Mr. SWALWELL. Thank you, Dr. Pielke. Thank you, Dr. Tol. 

Mr. SCHWEIKERT. Thank you, Mr. Swalwell. 

Mr. SWALWELL. I yield back the balance of my time. 

Mr. SCHWEIKERT. Representative Brooks. 

Mr. BROOKS. Thank you, Mr. Chairman. My questions are for 

Drs. Botkin and Pielke. 

Testimony includes an image of 102 model runs done by John 

Christy of the University of Alabama in Huntsville, which is where 

I reside, in Huntsville, including those used by the IPCC and the 

White House Climate Assessment for Global Temperature from 

1975 to 2025. For the period 2000 to the present, how many of 

these models have accurately projected actual observed temperatures? 

Dr. BOTKIN. Well, that graph was to some of them but I also 

have been in contact with John Christy and he sent me other 

graphs that show in particular how the American—U.S.-based 

models have done and they haven’t done any better. I can’t speak 

to all of them. Actually, it is 102 model runs and about 34 models. 

But even the U.S. models don’t do well at all. They don’t even come 

close. 

Dr. PIELKE. You know, on the figure have in my written testimony that John Christy graciously provided me, you can see the 

couple of models are close to what has been observed in the last 

20 years, 15, 20 years, but by far the vast majority have overstated 

the warming. 

Mr. BROOKS. Well, why does it matter that these climate models 

have failed so frequently? 

Dr. PIELKE. Well, it is one of the tests of the model. I mean if 

you are going to use these models to try to predict what will happen in the next several decades, you want to have some confidence 

that they are robust tools. And I think the models have failed to 

show that. In fact, I think they have been a cause for a lot of debate and discussion. 
79 

And I think what Michael was saying we don’t probably need the 

models because the models are misleading us. They are talking 

about a future that may not occur. It certainly hasn’t shown that 

the models are able to replicate what has happening the last several decades, and so you wouldn’t believe a weather prediction 

model that was forecasted for tomorrow or the next day if it kept 

failing all the time. I think that is what we have with these climate 

models. They are not ready for primetime. 

Models are very useful. They understand processes. They can 

help assimilate data. But as forecasting tools decades into the future, they are not ready. 

Mr. BROOKS. Dr. Botkin, do you have anything to add? 

Dr. BOTKIN. Yes. And, first of all, the models are well known not 

to be very well validated for—at any level, and there is work such 

as by J. Scott Armstrong who is an expert on model validation 

mainly for businesses and he says that these climate models meet 

hardly any of the criteria for legitimate validation. And so you 

can—you have to question the validity of the model. 

And I say this having worked on some of the models. I had a 

graduate student that added vegetation to one of the climate models as his Ph.D. thesis, so I think that the models, since they are 

so much failing to come close and haven’t been well validated, they 

are not a good guide now. 

Mr. BROOKS. Well, we have used this 97 percent of scientists 

agree kind of number. Is it fair to say that close to 100 percent of 

scientists agree that our models are failures? 

Dr. PIELKE. No. A lot of people—obviously they don’t believe they 

are failures because they base the IPCC and the—— 

Mr. BROOKS. Well—— 

Dr. PIELKE. —National Climate Assessment on it. 

Mr. BROOKS. —let me be more specific. That for the time frame 

from 2000 to 2014 that they have failed? 

Dr. PIELKE. I would think someone would still disagree. They 

have been trying to explain how they can—why they are not agreeing, why there is less warming. They say now the warming has 

gone deeper into the ocean, for example, which obviously raises the 

question if it has gone deeper in the ocean, why didn’t they predict 

that? But I would think there are people that are still arguing the 

models are robust. 

Mr. BROOKS. Well, I am looking at the graphs. Is this graph accurate? 

Dr. PIELKE. Yes, the graph is accurate. 

Mr. BROOKS. Well, the graph shows that the models don’t correspond with actual temperatures, so how can people contend that 

the models are good if they are way off base with the temperatures 

with the exception of perhaps one or two out of all the models 

being run? 

Dr. PIELKE. That is an excellent question, but I think it is even 

broader than that because, as I did in my—as I showed in my written testimony, there are a range of peer-reviewed papers that have 

shown when these models have run in the last several decades, 

they can’t predict regional statistics well at all. They can’t predict 

changes in regional climate statistics, and therefore, there is a 
80 

whole range of reasons they shouldn’t be accepted. But the problem 

is this issue is not being discussed. It wasn’t discussed in the IPCC. 

Mr. BROOKS. Let me conclude with this question. Former Vice 

President Al Gore recently gave an interview to Politico in which 

he stated that ‘‘extreme weather events’’ are 100 times more common today than they were 30 years ago due to global warming. He 

also stated that these events are ‘‘getting more frequent, more common, bigger, more destructive.’’ Do you agree with this statement 

and is a consistent with the state of the science? Dr. Botkin first 

and then Dr. Pielke. 

Dr. BOTKIN. There is very good data—and Dr. Pielke and his son 

can provide them—that show that the average rate of tornadoes, 

hurricanes, droughts are within the range of what has happened 

in the past. It is not extreme. And I would add that as a now resident of Florida, there hasn’t been a major hurricane hit the mainland of Florida for nine years, so somehow at least us in Florida 

are managing our climate. 

Mr. BROOKS. Dr. Pielke. 

Dr. PIELKE. I would refer you to my son’s testimony last summer 

to the Senate. I mean it is in area he is an expert in and he has 

commented quite a bit about this subject. 

Dr. BOTKIN. There was also another analysis that showed that if 

you looked over the Antarctic ice core data and then compared it 

to the recent changes, that the recent changes in climate are not 

outside the ranges of past climate. There is a published paper that 

shows that. 

Mr. SCHWEIKERT. All right. Mr. Brooks. 

Mr. BROOKS. Thank you, Mr. Chairman. 

Mr. SCHWEIKERT. Thank you, Mr. Brooks. 

Mr. Kennedy. 

Mr. KENNEDY. Thank you, Mr. Chairman. 

Dr. Tol, I think you have been clear about this but I just want 

to make sure that I have understood. You would agree with the 

statement that climate change is caused—or at least partially 

caused by greenhouse gases and that—I think you said earlier, 

most scientists agree that climate change is real. Is that true? 

Dr. TOL. That is true. 

Mr. KENNEDY. Okay. Dr. Oppenheimer, you believe that climate 

is changing. I think that is a safe assumption based on your testimony earlier? 

Dr. OPPENHEIMER. Yes. 

Mr. KENNEDY. Okay. The majority posted a chart earlier in this 

hearing that showed by some models anyway—and we will get to 

the reliability of those models in a second—but the end of—by the 

end of the century they predicted I believe it was a three degree 

centigrade change in global temperature. Can you color that a little 

bit for me? What does a three degree centigrade change in global 

climate temperature mean, Dr. Oppenheimer? 

Dr. OPPENHEIMER. Well, just to give you an example, already 

with less than a one degree—and we are talking degrees Celsius 

here so you double it roughly for Fahrenheit, with a change somewhat less than one degree Celsius, the number of extremely hot 

days—and by the way, in response to the last set of questions, one 

extreme that we are sure about that has increased are very hot 
81 

days. Those have definitely increased. We have a lot of confidence 

in that. 

The number of such extremes—for instance, in a city like Washington where a 90 degree day might be the hottest ten percent of 

days, such days have already become more frequent on the global 

average. The historical ten percent hottest days now represent 18 

percent of days, and so we are moving to a hotter and hotter climate where we have more and more extremes of high temperature. 

The sea level has been rising. The sea level has been rising primarily because water expands when you heat it and because ice is 

melting—— 

Mr. KENNEDY. So three degrees centigrade change in global temperature, any rough prediction as to what that means for sea level 

rise? 

Dr. OPPENHEIMER. Yes. It means a sea level rise which IPCC 

reckons will be something between almost a foot and three feet 

higher than today. And just to give you a rule of thumb, on an East 

Coast beach one foot of vertical sea level rise takes away in erosion 

and submergence typically 100 times as much land. One foot up 

this way, 100 feet inland go away unless you spend a heck of a lot 

of money defending the beaches. 

Mr. KENNEDY. Thank you, Doctor. 

And, Dr. Botkin, your testimony—written testimony you say 

that—I think your point one is that we are living through a warming trend but it is driven by a variety of influences. In part three 

you say, ‘‘Has the temperature been warming? Yes, we have been 

living through a warming trend, no doubt about that.’’ And part 

five you say, ‘‘Are greenhouse gases increasing? Yes, CO2 rapidly.’’ 

You go on to say in part three change is normal on life. Or ‘‘Change 

is normal. Life on Earth is inherently risky and always has been.’’ 

Doctor, do you look both ways before you cross the street? 

Dr. BOTKIN. What is the relevance of that question? 

Mr. KENNEDY. Do you wear a seatbelt when you get in the car? 

Dr. BOTKIN. Of course I do. 

Mr. KENNEDY. So do you think it makes sense to mitigate 

against some of these changes that you indicate are—in your own 

testimony are taking place? 

Dr. BOTKIN. I think that we—— 

Mr. KENNEDY. Yes or no, Doctor. 

Dr. BOTKIN. Yes or no? 

Mr. KENNEDY. Yeah, yes or no. 

Dr. BOTKIN. Okay. Restate the question. 

Mr. KENNEDY. Do you think—if you look both—if life is inherently risky, yet during the course of your daily activities you take 

steps to mitigate those risks, why would something that could be 

as catastrophic as climate change could be, why would we not take 

mitigating steps? 

Dr. BOTKIN. That is not a yes-or-no answer. There is no yes or 

no to that. 

Mr. KENNEDY. Well, would you suggest that we take mitigating 

steps or not? 

Dr. BOTKIN. I—if we—— 

Mr. KENNEDY. That is a yes or no. 

Dr. BOTKIN. We should do adjustments—— 
82 

Mr. KENNEDY. So yes. 

Dr. BOTKIN. —mitigate. It is very unlikely to work. So reducing 

carbon dioxide is unlikely to actually take place well within—— 

Mr. KENNEDY. I didn’t ask that. So what other mitigating steps, 

short of—if you are saying CO2 reduction, isn’t going to mitigate 

climate change, what other mitigating steps would you suggest? 

Dr. BOTKIN. I suggest that we deal with the situation by reducing the—going back to the major issues that face us. There are 

nine major environmental issues that affect us all the time and are 

much more damaging and much riskier to us than climate change, 

and I would be happy to give you those. And we need to focus on 

those. 

Mr. KENNEDY. Okay. 

Dr. BOTKIN. And if we focus on those, they are either neutral or 

beneficial to the global warming—— 

Mr. KENNEDY. Okay. So in your opinion, Doctor, climate change 

is not one of the top nine greatest environmental changes—challenges we face? 

Dr. BOTKIN. I have been working on climate change since 1968 

and I think it is one of the problems we need to deal with but we 

have to put it in its proper priority with those other nine. 

Mr. KENNEDY. Sir, I have got—— 

Dr. BOTKIN. I am not saying that—— 

Mr. KENNEDY. —eight seconds left so let me ask—— 

Dr. BOTKIN. —we should ignore it. 

Mr. KENNEDY. —one question for Dr. Pielke. 

Sir, you have said that humanity has had a significant effect on 

climate. You have talked a little bit about whether—the faith that 

we put in these models and the models but I think you said are— 

also aren’t working and I think there is some question as to how 

reliable and how accurate these models are concededly. You mentioned in your written testimony that—some of the National 

Weather Service funding and the models that have been created by 

that, have had enormous social value. Do you think those—investment in those types of models is a good thing? 

Dr. PIELKE. Yes, I do and I think investment and predictability 

of climate models is also an excellent investment. That is different 

than providing—— 

Mr. KENNEDY. Understood. Understood. So how would you categorize the decision to cut NOAA climate funding by 24 percent, 

which is what the appropriations bill that we will be voting on this 

afternoon would do? 

Dr. PIELKE. I think there is an issue—what you are calling climate change and there is climate. Climate—— 

Mr. KENNEDY. I am just saying the study, it is about funding 

for—— 

Dr. PIELKE. Well, I can’t—obviously can’t answer that question 

unless I know exactly where the funding is going to. But if it is 

funding predictive models for decades in the future, I don’t think 

that is a good use of funds. 

Mr. KENNEDY. Thank you. 

Dr. BOTKIN. Could I comment a little more about your question? 

Mr. SCHWEIKERT. Mr. Botkin, actually I have to move on, too. 

Mr. Cramer. 
83 

Mr. CRAMER. Well, I might give Dr. Botkin a chance actually to 

answer it because, Dr. Botkin, what I would ask you as a followup to Representative Kennedy’s question is if wearing your seatbelt 

increased your likelihood of surviving the crash by 0.08 percent but 

you were likely to lose your job as a result of it, would that be a 

good mitigation? 

Dr. BOTKIN. No. Apparently not. But I always wear a seatbelt 

so—— 

Mr. CRAMER. Because the percentages are much better than that. 

Dr. BOTKIN. Yes. Yes. But, look, I have written a lot about risk 

in life and how you deal with it. I have developed a computer 

model of forest that has risks. But think about—of course you want 

to deal with risk but think about how an impala in Africa deals 

with risks. These animals often know when a lion is hunting them 

and then they will move away, but once a kill has been made, then 

you will see the grazers grazing near the lion because it is no 

longer a threat. 

So there is a book that says that is why they don’t—part of the 

reason they don’t get ulcers. You have to know when to respond to 

risk and what are real risks and how to deal with them. I have 

written a lot about them so it is not appropriate to say just because 

risk is real means I need to—that you ignore it. No. You say risk 

is reality. Now, where are the risks that we must reduce? Where 

are risks unacceptable for our human lives? And for example, right 

now, there is huge habitat destruction. There is invasive species 

that are threatening the entire citrus crop in Florida. That is a 

major risk that we need to deal with now. Our fisheries are in big 

trouble. There are major risks with them. We want to reduce those 

risks. So you have to know about risks, understand how to analyze 

it, use the mathematics, the statistics processes. You are very alert 

to risk. Just to say there is risk doesn’t mean you ignore risk—— 

Mr. CRAMER. Yeah, we often don’t do a cost-benefit analysis and 

we frankly create more risks by mitigating the risks that we think 

we are avoiding. 

I want to get to the issue a little more of peer review and peer 

pressure if you will. And, Dr. Pielke, you referenced your son’s testimony in the United States Senate. Of course the President’s 

Science Advisor Dr. Holden has been critical of I think your son’s 

testimony and in fact has stated, I don’t think in the context of 

your son’s testimony, but stated that anybody who disagrees with 

their premise makes themselves out to be ‘‘silly.’’ Perhaps you could 

just elaborate a little bit on how—what kind of signal does that 

send from the top of our leadership to the scientific community that 

if you disagree with me you are somehow silly? 

Dr. PIELKE. Well, it is not healthy for the scientific process and 

it is probably not—certainly not healthy for the political process. 

But I have had my own experiences. I was asked to be on the 

American Geophysical Union Committee on Climate Change and 

we put together a statement I could not agree with. It was very— 

I think sort of like a National Climate Assessment type statement. 

And I wrote a minority statement on that and I put it as an appendix in my testimony, but it wasn’t reported in the Journal of the 

American Geophysical Union. They wouldn’t publish that particular statement. And so I think there has been a chilling effect 
84 

on presenting alternative perspectives, and actually I was a sort of 

intrigued that Michael was talking about maybe the need for another team. Maybe there should be a red team that try to come up 

with other perspectives challenging these reports and maybe together we could create a better consensus than what is available 

now. Because now if you stand up and you make a view that is different, you get either ignored or you get dismissed. 

Mr. CRAMER. Well, Dr. Pielke, you make a great point. And I was 

very encouraged by Dr. Oppenheimer’s statement about transparency because that is what this hearing is all about. And one of 

the things I have found in this place is that the lack of transparency creates way more mistrust than honest discussion of 

even—in fact, one of the things I think I rather am proud of is that 

I like to hear the opposing view, and if I talk to four advisors and 

they all agree with me, I try to find a fifth one, otherwise I just 

don’t think you have the type of robust and honest discussion that 

you need to get the consensus. 

And, Dr. Tol, I would be interested in your opinion as well on 

what happens to people who disagree, especially in the academic 

world. I mean how does this peer pressure play itself out if we 

don’t have greater transparency, more robust opposing discussion? 

Dr. TOL. For people who disagree on climate or on climate policy 

are sorted disinvited or not invited or ignored. Their papers can get 

into trouble, their funding can get into trouble, they can be 

smeared in the media, and so on and so forth. And it even goes as 

far as that they are personally threatened or their family is threatened. And I think it is very unfortunate and very unhealthy. 

Mr. CRAMER. I agree. Thank you. Thank you all. 

Thank you, Mr. Chairman. 

Chairman SMITH. Thank you, Mr. Cramer. 

And the gentleman from Texas, Mr. Veasey, is recognized for 

questions. 

Mr. BERA. Marc, can I take it? 

Chairman SMITH. Of course. I assume the gentleman from Texas 

will defer to the gentleman from California, Dr. Bera. And so Dr. 

Bera is recognized for his questions. 

Mr. BERA. First, I want to thank my colleague from Texas for 

that. 

My thought process here—this is a fascinating hearing. We agree 

that the climate is changing and I think all of our colleagues agree 

that the climate is changing and all of our witnesses certainly have 

agreed to that as well. Now, what is causing that change we can 

debate. You know, is it cyclical, is it natural, is it human? For the 

record, I do think humans have impacted climate change and our 

behaviors impact on our accelerating climate change. 

Dr. Tol, you touched on the danger of groupthink. And I come out 

of academia. I am a biological scientist before going to medical 

school and getting my M.D. And there is a danger for groupthink. 

Groupthink, hundreds of years ago, said the Earth was flat. So 

part of advancing science, part of academia is challenging 

groupthink, is inviting all views in a nonjudgmental way. The scientific method requires that we explore and engage in this debate. 

There is consensus as well. I am from California and we are 

going through an incredibly bad drought here this year. We have 
85 

very wet years as well in my region and flood so we know we have 

to—you know, when we talk about risk and mitigating risk, we 

have to assess risk, we have to look at how we can mitigate that 

risk, how we can do the things that are within our control to better 

manage that risk and there is no model of predictability that is 100 

percent but, we sit there and say, okay, well it looks like it is going 

to be a dry year next year. Let’s try to manage that risk and mitigate that risk. It may be a wet year. But we do our best with the 

data that is available and we invite that conversation. 

So I think this is incredibly important. We all agree the climate 

is changing. The objective data says the globe is getting warmer. 

You know, we are having weather extremes. Dr. Botkin talked 

about impacts on agriculture, such as the impacts on our fisheries. 

So let’s just acknowledge these risks and let’s have an adult conversation about how we can mitigate and what we can do. 

Now, my question. Dr. Oppenheimer, you touched on a real issue 

that does concern me. You know, we already have quite a significant amount of CO2 trapped in our atmosphere and we have had 

our Secretary of Energy in here and you also commented on how 

long it will take to degrade that, hundreds of years to degrade the 

CO2 that is already trapped in our atmosphere. From your perspective within the IPCC and within the scientific community, that to 

me there is an urgency in advancing the science of how we might 

go about degrading these masses of carbon. And, yeah, I pass that 

over to you. 

Dr. OPPENHEIMER. Yeah. I mean what I am concerned about— 

and Mr. Kennedy asked me about this—is what does the world look 

like if you just let this keep going on and you get past 3 degrees? 

And the things I would worry about the most are food supply particularly in poor or low latitude countries, but also if you just let 

it go on indefinitely, global food supply; secondly, extreme heat, as 

I mentioned before; third, particularly in the context of all the 

other problems that humans are causing for species and ecosystems, the pressure of a rapid warming on species and ecosystems. Some are already very sensitive like coral reefs and the 

Arctic systems are already under threat and that involves just also 

the people that depend on them, not just the other species; and 

fourth, what is going to go on along the coast where we know how 

vulnerable our coast is. 

So that is the picture of the world when you get 3 degrees and 

beyond that I am worried about. And if you look at the scenarios 

about how you would avoid that world, you really have to get going 

now with some substantial reductions in emissions. 

Mr. BERA. Dr. Botkin, would you want to—— 

Dr. BOTKIN. Yes. Mr.—Dr. Oppenheimer has just misstated some 

things. You know, I do work on the Arctic and I have friends—colleagues who work there, including Craig George, who lives up in 

Barrow—lives up in the very north end of Alaska. And anyway—— 

Mr. BERA. You wouldn’t disagree that the Arctic is changing, 

though, would you, that ice is melting, that—— 

Dr. BOTKIN. Well, we did a study in which we used the records 

from logbooks from whaling ships hunting the bowhead whales in 

the 19th century and compared it with late 20th century and we 
86 

found two things. We found that the end of winter sea ice extent 

was the same in the 19 century as by the end of the 20th century. 

Mr. BERA. But it has changed over the last decade so it may have 

changed 200 years ago but there is change occurring. 

Dr. BOTKIN. There are changes but it has happened in the past. 

In fact, the Northwest Passage has opened before. We know that 

because there is DNA from bowhead whales in Atlantic—relatives 

of them which couldn’t have happened. So these kind of changes 

have happened in the past. 

And as I point out, the evidence about polar bears is really negligible. So there are changes. The question is whether these 

changes are really damaging or not and the evidence is not strong 

that it is damaging. 

Mr. BERA. I have gone over my time so again thank you to my 

colleague from Texas. 

Chairman SMITH. Thank you, Dr. Bera. 

And the gentleman from Arizona Mr. Schweikert is recognized 

for his questions. 

Mr. SCHWEIKERT. Thank you, Mr. Chairman. 

I wish we were just sitting around the table not drinking beer 

because we know what happens then, but drinking coffee, and just 

be able to have an extended dialogue. One of my concerns is actually an odd one for a guy that is elected to Congress is we live in 

a two-year cycle, politics. When you deal with other countries, their 

parliamentary systems, they never know when their next election 

may be. We are in a political environment. You are trying to do in 

many ways data, maybe not even policy but do data, and yet those 

of us in the political world, we now control so much of the money 

that the academic community has access to. And one of my future 

goals here is trying to find a way to sort of separate the implied 

or actual sort of influence because, let’s face it, the whole discussion here and the policy outcomes from this are stunning amounts 

of money to be made or to be lost depending on the country, the 

industry, the technology, how people have invested. And every single Member of Congress here has had someone in our office saying 

please regulate this, please do this because this is how I invested. 

As my father used to say, it is about money, power, ego and I am 

finding often it is all about all three. 

There is actually a couple externalities I want to get my head 

around. I will try to speak actually faster. And this is sort of open 

to anyone on the panel. If I walked into you and said here is my 

incremental amount; here is $10 billion and I want to maximize 

beneficial effects over the next five years, so let’s do a limited time 

frame, would I be focusing on A-CO2? Would I be focusing on 

invasive species? Would I be focusing—my fear is because of the 

size and scale of this issue, we may be heading towards a 

misallocation of resources. 

Let’s just start, Dr. Pielke. Talk to me a little bit about my 

threat levels in allocations of resources and how we do sort of risk 

analysis? 

Dr. PIELKE. I think that is really an excellent question. That gets 

up to this approach that we have been proposing where it is what 

I call a bottom-up resource-based perspective where you try to reduce risk to your important resources. So for Arizona, for example, 
87 

it is probably going to be water would be one of your big ones. How 

can you improve your water infrastructure so that you are robust 

against periods of drought? 

Mr. SCHWEIKERT. Okay. 

Dr. PIELKE. To me that is the single—probably number one item 

I would look at. 

Mr. SCHWEIKERT. Dr. Botkin. 

Dr. BOTKIN. Yes. I agree. We should focus on these issues I mentioned before. Freshwater is one. We are overusing worldwide 

freshwater and we have to reduce that. You would be surprised to 

know that phosphorus for agriculture is a limited resource. There 

is going to be a lot of competition for that. We need to focus on 

that. Habitat destruction is very destructive but in many ways—— 

Mr. SCHWEIKERT. But where I am heading more is—conceptually 

is my ranking because my great fear is we spend lots of time on 

CO2 and issues involved in there and something slips through the 

crack that becomes much more—— 

Dr. BOTKIN. I would say you want to focus on these. I would start 

right now on invasive species. I think that the climate issue should 

be put—reduced and its priorities in favor these kind of issues. 

Mr. SCHWEIKERT. Dr. Oppenheimer, if you were looking at limited resources in your prioritization—I am not saying you walk 

away from one—what would you be right now? 

Dr. OPPENHEIMER. Within the context of the climate issue, I 

would balance money spent on finding ways to reduce emissions 

quickly and cost-effectively—— 

Mr. SCHWEIKERT. But even outside climate. 

Dr. OPPENHEIMER. There are so many things—— 

Mr. SCHWEIKERT. And if I gave you a five year window because, 

let’s face it, we live in two year windows so five years is forever 

for us. And I said here is my resources, go do something great, 

what would you do? 

Dr. OPPENHEIMER. Climate would be a part of the picture; it 

wouldn’t be the whole picture. And in dealing with climate I would 

deal with both reducing CO2 and protecting people from climate extremes that are already happening—— 

Mr. SCHWEIKERT. But there would be a variety of things on your 

list? 

Dr. OPPENHEIMER. Of course. 

Mr. SCHWEIKERT. Dr. Tol. 

Dr. TOL. For a five-year timescale and for a global perspective I 

would go for Golden Rice. 

Mr. SCHWEIKERT. Okay. High-yield—— 

Dr. TOL. Yes, high yields in vitamin A because that would save 

most lives in this timescale. It would also reduce vulnerability to 

climate change. My second priority if it were a 15-year timescale 

would be a malaria vaccine which also would reduce the vulnerability to climate change but would do much good in itself. 

When you are talking about 50- or 100-year time frame, then climate change would come into the picture. 

Mr. SCHWEIKERT. Okay. It is—actually amazed you said the rice 

because that has actually been one of my interests. 
88 

Dr. Oppenheimer, just a quick reference, noise in the data, I 

have a great interest in sampling. One of the noises we were looking at years ago was we see urban high temperatures—— 

Dr. OPPENHEIMER. Um-hum. 

Mr. SCHWEIKERT. —going up but when we actually looked at 

where the samples were being taken, we were seeing concrete islands, heat sink islands, regeneration islands and trying to find a 

methodology to adjust for that meaning that we actually had a lot 

of noise in urban temperature data. 

Dr. OPPENHEIMER. That—— 

Mr. SCHWEIKERT. When you work on the committee, are you constantly looking for where there are these externalities that are creating noise in your data? 

Dr. OPPENHEIMER. Yes. They are constantly looked at. And that 

particular one, which was interesting a couple of decades ago, has 

been resolved. There is an urban heat island effect. 

Mr. SCHWEIKERT. Um-hum. 

Dr. OPPENHEIMER. However, its effect on the global temperature 

trend of about .9 degrees Celsius over the last 100 years has only 

been less than .1 degree at the North Pole. 

Mr. SCHWEIKERT. Yeah, but in recent sample sets they are still 

using the current temperature from those urban areas instead of 

doing—— 

Dr. OPPENHEIMER. No, there are different ways it is done and 

they removed those to the extent they affected data significantly. 

Mr. SCHWEIKERT. I would love to look at that because I can show 

you some of the data sets where it wasn’t adjusted 4. 

Dr. OPPENHEIMER. I would be happy to—— 

Mr. SCHWEIKERT. I yield back, Mr. Chairman. 

Chairman SMITH. Thank you, Mr. Schweikert. 

The gentleman from Texas, Mr. Veasey, is recognized for his 

questions. 

Mr. VEASEY. Mr. Chairman, I have an article from the Wall 

Street Journal. It is a MarketWatch I would like to submit for the 

record. The article expresses concern and frustration with an 

amendment passed last week by my Republican colleagues as part 

of the National Defense Authorization Act which restricts the Pentagon’s use of climate science studies, including the IPCC which we 

are discussing today, as part of its strategic military planning. The 

article in the Journal states that ‘‘GOP science deniers have 

’crossed the line,’ they are now messing with national security. 

America is now under attack from an enemy within, irrational 

science denialism, a toxic mindset, a spreading self-destructive 

mental virus. Yes, this is ‘War on America’.’’ The military has been 

using this for—this science—this climate science research for decades now and the research studies show that they are an essential 

part of our national defense. And, Mr. Chairman, because of that, 

I would like to move to include this article as part of the record. 

Chairman SMITH. Without objection, that article will be made a 

part of the record. 

[The information appears in Appendix II] 

Mr. VEASEY. And I have a question for Dr. Botkin—excuse me if 

I pronounced the name wrong—Dr. Pielke and Dr. Tol. You all cite 

John Christy as an example of someone whose model should be 
89 

considered in the IPCC process. Christy famously used tropospheric 

temperature records from satellite data to show little evidence of 

warming. Those results were challenged by two peers resulting in 

Dr. Christy acknowledging very serious errors in his data and correcting these results, which meant that his models then showed 

warming. Somehow, since this acknowledgment in Science magazine, Dr. Christy has returned to showing no significant change in 

global temperature. 

My question for you is which Christy models should the IPCC 

rely on? 

Dr. BOTKIN. Could I just—— 

Dr. PIELKE. Well, let me mention that one. I worked closely with 

John Christy. I was there when that error was discovered. It was 

not a major error. He corrected it and everything since then has 

moved forward. In fact, he actually has a slightly more warming 

than the RSS data, which is another group that analyzes tropospheric data. These are not models. He is working with satellite 

data so it is not a model. His model comparisons are taking the 

models that are available to anyone from the IPCC. 

So John Christy’s work is accepted as being robust by the entire 

scientific community. I am not aware of anyone that is critical of 

what he has shown. The—there is other evidence also presented 

about the models that I presented in my written testimony that 

shows there are problems with the models. 

Mr. VEASEY. So which models do you think he should be using, 

the ones that he retracted, the ones that are consistent—— 

Dr. PIELKE. No, I can—— 

Mr. VEASEY. —with other researchers or the ones that mysteriously are consistent with his earlier work? 

Dr. PIELKE. No, I have to correct that he did not—he does not 

use a model in his analysis of the tropospheric temperatures; he 

uses satellite data. These are observational data sets. He then compares it with model results that are computed by other people. 

There is a whole range over in my written testimony that he provided to me that are the models that are used to create the National Climate Assessment, models that are used to create the 

IPCC report. So there are—that is not his model. His model is robust, always has been robust. It was a small error that he found 

and it has been apparently blown out of proportion. 

Mr. VEASEY. Dr. Oppenheimer, would you please comment? 

Dr. OPPENHEIMER. There were a couple of adjustments that Dr. 

Christy had to make, but I think the more important point is that 

if you look at the IPCC report, they actually have a lengthy discussion of the difference between what models project and what Dr. 

Christy’s data and other people’s show for the warming in what is 

called the mid-troposphere, which is only a small slice of the atmosphere, over the last 35 years. And there are discrepancies not 

just between the models and the data but between different data 

sources. 

This is an area of uncertainty. It is an area that has been looked 

at extensively. It is an area where the uncertainties are not completely resolved and it can’t be used to undermine the credibility 

of the models, particularly because the observations themselves are 

disparate. So this is an example of where IPCC actually has this 
90 

stuff in the background report, looked at it, assessed it, and will 

continue to do so over the next series of assessments. 

Dr. PIELKE. And I correct Michael a little bit. The data that John 

Christy provided me is lower tropospheric data. 

Dr. OPPENHEIMER. Fine. 

Mr. VEASEY. Thank you, Mr. Chairman. I yield back. 

Chairman SMITH. Thank you, Mr. Veasey. 

The gentleman from Georgia, Dr. Broun, is recognized for his 

questions. 

Mr. BROUN. Thank you, Mr. Chairman. 

Gentlemen, I am a medical doctor, a physician. I would submit 

that that is a scientist, an applied scientist. It is not the same as 

a research scientist obviously but I was trained in the scientific 

process. And I have got some problems with some terminology that 

is utilized particularly by folks that are researchers, people on the 

other side of the aisle here, and from my scientific background this 

notion of settled science to me is totally unscientific on its face. 

And so I would like to start with Dr. Botkin. Would you agree 

with my last statement? 

Dr. BOTKIN. Absolutely, and I have run workshops on cancer research and have a lot of friends in medical research, and I would 

like to add that I think that medical research and ecological research share a lot in common and I agree with you completely, 

yeah. 

Mr. BROUN. Dr. Pielke, would you agree with that statement? 

Dr. PIELKE. The science is not settled, no. 

Mr. BROUN. Dr. Oppenheimer? 

Dr. OPPENHEIMER. Some things are more or less settled; some 

things are not. 

Mr. BROUN. Well—— 

Dr. OPPENHEIMER. The question of whether carbon dioxide is 40 

percent above preindustrial times, that is settled. The question of 

exactly how warm the Earth will become as a result, that is not 

settled. 

Mr. BROUN. Well, Dr. Tol? 

Dr. TOL. Science is of course never settled but, as Michael 

Oppenheimer says, there are thoughts that everybody basically 

agrees on and there are parts of science where everybody disagrees 

essentially. And that is what we should focus on in our research. 

Mr. BROUN. Well, the point of all this is that the idea of settled 

science, Mr. Rohrabacher talked about ‘‘case is closed.’’ I heard it 

just on the Floor yesterday from Members of the other party, they 

were talking about this very issue that it is absolutely settled, it 

is a closed case, there is no question whatsoever that we have 

something called anthropogenic global warming. And of course the 

terminology has changed from human-induced global warming to 

anthropogenic global warming, now to anthropogenic climate 

change. Climate changes all the time. Of course it is called weather. 

To go back to the IPCC report, I have seen in medical science 

and papers that are written, there is a lot of selectivity as far as 

what papers are considered to be valid and what is not, what is 

published and what is not, what peer review is accepted and what 
91 

is not. Data and assumptions and methodology all come to play in 

these. Would you all—— 

Dr. BOTKIN. Could I comment on that? 

Mr. BROUN. I will come to you and just a second, Dr. Botkin. 

Would you all agree with that statement? 

Dr. BOTKIN. Yes. 

Mr. BROUN. Everybody agree with that statement? 

Okay. Dr. Botkin, you had a comment. 

Dr. BOTKIN. As I said, I have worked on this since 1968, and in— 

by the mid-1980s the weight of evidence, as far as I was concerned, 

was heavily in favor that there was a human-induced climate 

warming and I gave talks and television interviews and—that said 

that. But since the middle of the 1990s the—there is evidence that 

is running against that. For example, the temperature change is 

not tracking carbon dioxide increase very well. I refer again to 

Christy’s information. 

Then there is the information from the Arctic long-term Antarctic 

ice cores that suggest—and from some recent papers in the Arctic 

that suggest that carbon dioxide change doesn’t lead temperature 

change. It may actually lag it significantly or may not lag it—may 

not lead it at all. And if that is the case, that is still an open but 

important scientific question. So there are several lines of evidence 

that are suggesting that it is a weaker case today, not a stronger 

case. 

Mr. BROUN. Dr. Pielke. 

Dr. PIELKE. The question about science being settled I think is 

an interesting one. We probably should find out where there is 

common ground where there is not. And I think in terms of what 

Michael and Richard were saying and Dan was saying, CO2 is increasing. There is a human component to it. Apparently it is not 

as closely connected to maybe the global temperature but there is 

a biogeochemical effect from added CO2. So there are concerns. The 

question is how does that fit and—in the other realm of concerns 

that we had from other human forces on the climate and other environmental issues? And that is the science issue that is not settled. But if you come up to an approach where we can come to common ground on some issues, we can move forward on others where 

we disagree. 

And in terms of political action, maybe all the information is already out there to deal with it. We know CO2 is increasing but it 

is—where does it fit in terms of the range of all the other threats 

and costs that we have? I think that is the issue that has to be 

resolved. 

Mr. BROUN. And how does that fit with policymakers because 

science cannot determine policy. 

Dr. PIELKE. I completely agree. 

Mr. BROUN. Yes. We have to take science, good science, and there 

is a lot of junk science out there, too. We have to take good science 

and take that into consideration and economic models have to come 

into play as far as we are concerned. 

And I don’t think from a policy perspective, what I see overwhelmingly, the people who want to make radical changes in public 

policy are liberals, and those of us who want to look at things from 

another perspective are more conservative. Why is that so? Why is 
92 

it that the liberals all say that we have got to make these huge 

changes that are going to affect our economy, it is going to affect 

job productions, et cetera, and they use IPCC reports, et cetera, to 

help bolster their claim and then we have Members that try to disqualify people with dissenting views. And to me that is unscientific 

and I think this whole discussion about settled science and how it 

is all said and done, case closed, period, is totally unscientific and 

I just encourage IPCC and those of you all who have the ability to 

make policy decisions there, not just one dissenting view but other 

dissenting views, scientific dissenting views across the board to 

publish those also. 

Chairman, my time is expired. Thank you. 

Chairman SMITH. Thank you, Dr. Broun. 

Dr. Bucshon, the gentleman from Indiana, is recognized. 

Mr. BUCSHON. Thank you, first of all, for all your valuable testimony. I was a medical doctor before coming to Congress, a surgeon, 

so analyzing data, analyzing studies in journals is something of 

course that you learn to do and you begin to realize that a lot of 

what is published is probably not accurate. And so that is my background just so everyone knows. 

Were there previous warming trends in—on the Earth predating 

the fossil fuel era of energy production? Dr. Botkin first and 

then—— 

Dr. BOTKIN. Yes. If you look at the Antarctic ice cores, they show 

times where it was warmer than today and then there—in recent 

times there was the medieval warming that may not have been as 

warm but it was a warming trend that had a big effect on people. 

It was the time of exploration. So there has been warming and 

cooling periods. 

Mr. BUCSHON. Dr. Oppenheimer. 

Dr. OPPENHEIMER. There have been warming and cooling periods. What is unique about this period is, number one, the rate. 

And—— 

Mr. BUCSHON. Thanks. I have already heard your opinion on 

that. 

Dr. OPPENHEIMER. Okay. Okay. 

Mr. BUCSHON. The question that I have, and anyone can answer 

it—start with Dr. Botkin—and it is why did the climate change 

then? 

Dr. BOTKIN. Well—— 

Mr. BUCSHON. Why was the temperature of the Earth warm then 

predating fossil fuel use? And just so you know, I am one that does 

believe the temperature of the Earth is changing, as it has for centuries. I am not one—I don’t—I am not one of the people that don’t 

believe that there are trends and the temperature of the Earth may 

very well be increasing at this time. I think the discussion is what 

the impact we are having on that versus historical temperature 

changes. 

Dr. BOTKIN. I can’t answer the question about the cause of the 

medieval warming but you do know that there is what are called 

the Milankovitch cycles, which have to do with the orbit of the 

Earth and how the Earth spins on its access that create long-term 

changes, 20,000, 40,000, 100,000 years. But what caused the medieval warming I don’t—— 
93 

Mr. BUCSHON. Dr. Pielke first and then Dr. Oppenheimer. 

Dr. PIELKE. Well, climate is always changing. Actually the word 

climate change is sort of an oxymoron because the climate never 

is—it has always varied over different time periods. But human activity does have an effect. CO2 adds things. But we are now recognizing there is a natural effect of large-scale warming over longer 

terms probably related to cloud processes that are poorly understood. So the climate system has become more complicated as we 

learn more about it and that makes it much more difficult to predict. But we know that humans have a role and there is a natural 

role and we are still trying to ferret out what the relative percentage—— 

Mr. BUCSHON. Dr. Oppenheimer. 

Dr. OPPENHEIMER. The natural climate changes occur due to the 

orbital changes that Dr. Botkin just noted, which happen over tens 

or hundreds of thousands of years. They happen volcanic dust particles reflect sunlight. But we can measure that. We know that that 

is not the cause of the current warming. They happen because the 

strength of the sun changes. We can also measure that, have been 

doing so for more than 30 years. 

Mr. BUCSHON. Okay. 

Dr. OPPENHEIMER. We know that is not the cause of the current 

warming. The only plausible cause is the human emissions of the 

greenhouse gases. 

Mr. BUCSHON. Thanks for that opinion. I tend to probably disagree but—— 

Dr. BOTKIN. The—— 

Mr. BUCSHON. —it is open, all of us should have this discussion. 

And I want to make some comments about someone else who was 

addressing the money. This issue is about money, and when you 

look at the State that I represent, the State of Indiana, which depends on coal for 85 to 90 percent of our power generation, this is 

a huge issue. And I mean you only have to listen to the testimony 

and the discussion from other witnesses about federal funding, 

when you try to not give federal funding to people that they support, what happens, how horrible that is, and when the Republican-controlled House doesn’t give money to people that support 

the Administration’s position on this particular issue, you see the 

outrage. 

Also, if you don’t think this is about that, look at some of the line 

of questioning. And Dr. Botkin, I am going to apologize on behalf 

of Congress for the really, I think, juvenile insulting questions that 

you had about seatbelts and other things, trying to disparage the 

credibility of distinguished panel members, no matter who that is, 

that should not be part of the discussion. The money should not be 

part of the discussion. What this should be about is science and I 

am hopeful that we—all of us on either side, whatever we believe, 

can stick to science. 

With that, Mr. Chairman, I yield back. 

Chairman SMITH. Thank you, Dr. Bucshon. 

And that concludes our Members who had questions. 

And let me thank all the panelists, all the witnesses today for 

their testimony. I think this has been particularly helpful to us. We 
94 

heard things we haven’t heard before and so the record is vastly 

improved because of your contribution. 

So thank you again and we stand adjourned. 

[Whereupon, at 12:59 p.m., the Committee was adjourned.] 
(95) 

Appendix I 

ANSWERS TO POST-HEARING QUESTIONS
96 

ANSWERS TO POST-HEARING QUESTIONS

Responses by Dr. Richard S.J. Tol 
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98 
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100 
101 
102 

Responses by Dr. Michael Oppenheimer 
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104 
105 

Responses by Dr. Daniel Botkin 
106 
107 
108 
109 

Responses by Dr. Roger Pielke Sr. 
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111 
112 
113 
114 
115 
116 
117 
118 
119 
120 
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122 
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124 
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126 
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(133) 

Appendix II 

ADDITIONAL MATERIAL FOR THE RECORD
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ARTICLE SUBMITTED BY CHAIRMAN LAMAR S. SMITH
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ARTICLE SUBMITTED BY REPRESENTATIVE MARC VEASEY
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Æ